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Posted: 3/29/2015 12:25:58 PM EDT
[#1]
I would rather have a bolt that's MPI'd, so I know it doesn't have incipient cracks in it when new, than a bolt that isn't tested but might have flaws that will show up while I'm firing the rifle I put it in. It's a $40 part, even with the better level of testing, so I really don't care if it only lasts 5,000 rounds before it shows those cracks. I don't want flaws to cost me damaged uppers, scars or worse. Mr. Knight knows precisely who made his bolts, probably from the original billet material through leaving his door in a complete rifle. Me? I don't know who made most bolts, and only by depending on the vendor standing behind the bolt being thoroughly tested do I have anything I can depend on for whether or not the bolt I buy is going to work.
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Posted: 3/29/2015 12:41:22 PM EDT
[#2]
Quote HistoryQuoted:
KAC disagrees with you... Quote HistoryQuoted:
KAC disagrees with you... HPT is a waste of time and money. It also reduces the life of the bolt. I have stated this analogy before but it is like wrecking a new car into a brick wall and inspecting the frame for cracks. It is an archaic process . The government and industry should do away with it and come up with more productive forms of standardized acceptance /quality control . MPI bolts every 5000 or so rounds would be much more productive. I got news for you guys bolts crack then they break. There is sometimes no way of telling how long a bolt will go after it cracks before it fails. Many of the bolts in your trusted guns out there are cracked.
C Reed Knight III Knight's Armament Co. http://www.knightarmco.com/ Well, how many of you guys and gals out there have the facilities to mag-particle inspect your bolts before you install it, and again after every 5000 rounds? I don't. I want assurance that the new bolt I buy does not have a flaw that will cause premature failure. I know after XXXX number of rounds it will need replacing. |
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Posted: 3/29/2015 12:51:07 PM EDT
[#3]
Quote HistoryQuoted:
Well, how many of you guys and gals out there have the facilities to mag-particle inspect your bolts before you install it, and again after every 5000 rounds? I don't. I want assurance that the new bolt I buy does not have a flaw that will cause premature failure. I know after XXXX number of rounds it will need replacing. Quote HistoryQuoted:
Quoted:
KAC disagrees with you... HPT is a waste of time and money. It also reduces the life of the bolt. I have stated this analogy before but it is like wrecking a new car into a brick wall and inspecting the frame for cracks. It is an archaic process . The government and industry should do away with it and come up with more productive forms of standardized acceptance /quality control . MPI bolts every 5000 or so rounds would be much more productive. I got news for you guys bolts crack then they break. There is sometimes no way of telling how long a bolt will go after it cracks before it fails. Many of the bolts in your trusted guns out there are cracked.
C Reed Knight III Knight's Armament Co. http://www.knightarmco.com/ Well, how many of you guys and gals out there have the facilities to mag-particle inspect your bolts before you install it, and again after every 5000 rounds? I don't. I want assurance that the new bolt I buy does not have a flaw that will cause premature failure. I know after XXXX number of rounds it will need replacing. I do 
Honestly, I have not done it yet to any of my BCGs, though. |
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Posted: 3/29/2015 12:56:29 PM EDT
[#4]
Quote HistoryQuoted:
This isn't quite correct. Yes it is one cycle, but it is one cycle at a higher level of strain than operational cycles. If you look at life cycle charts for metals they they are not flat. Conceivably a hpt could use up considerably more than 1 operational cycle. I don't know squat about ar bolts or their stress levels or service life. I do know something about metal fatigue. Hpt seems as though it could sort out a substandard part, but at the cost of some operational life. Quote HistoryQuoted:
3) since proof testing is almost always above the fatigue limit it will affect the fatigue life. It reduces the fatigue life by one cycle out of 6000 plus or minus a few hundred. This isn't quite correct. Yes it is one cycle, but it is one cycle at a higher level of strain than operational cycles. If you look at life cycle charts for metals they they are not flat. Conceivably a hpt could use up considerably more than 1 operational cycle. I don't know squat about ar bolts or their stress levels or service life. I do know something about metal fatigue. Hpt seems as though it could sort out a substandard part, but at the cost of some operational life. Yes, they are not flat, but the rise is because the average strain is higher. Over the course of 5000 rounds the one 125% overload is not going change the average strain in any way, and the fatigue life will not be affected by any measurable amount. Aircraft are designed to last so many flight hours, just because they run in to some passenger bouncing weather, one day, does mean the engineers have to run back and redo the fatigue life. |
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Posted: 3/29/2015 1:01:58 PM EDT
[#5]
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Honestly, I have not done it yet to any of my BCGs, though. Okay, that's one. Can I send you my bolts every 5000 rounds for a check? (for free, of course) |
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Posted: 3/29/2015 1:04:13 PM EDT
[#6]
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Okay, that's one. Can I send you my bolts every 5000 rounds for a check? (for free, of course) Quote HistoryQuoted:
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Honestly, I have not done it yet to any of my BCGs, though. Okay, that's one. Can I send you my bolts every 5000 rounds for a check? (for free, of course) Sure. You may not like my fee, however. 
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Posted: 3/29/2015 1:21:00 PM EDT
[#7]
Of course not, presuming the flight load levels are within design specs. They do however account for any proof test loading in calculating overall design life.
Strain levels at notches, corners can be substantially higher than average field strain and will lead to crack initiation. A part limited to 6000 cycles at a given strain level would have a much lower life at 125% of that strain level. Proof testing accumulates damage at a higher rate than nominal loads, probably not a lot for a single overload, but it does accumulate somewhat accelerated damage. I dont know enough about mpi to know if the part is not cracked, but very close to crack initiation, if mpi can detect changes in the metals structure. I used to work with various inspectors on critical welds trying to determine what kind of smart flaw could exist within a weld - then do fracture analysis or flaw growth analysis to see if that flaw could potentially propagate and fail within the design life of the part. Our welds were radiographically inspected, dye penetrant inspected, and/or ultrasonically inspected - they all have their limits as to what they will find reliably. |
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Posted: 3/29/2015 1:25:45 PM EDT
[#8]
bolts are MP tested for a reason.
come on people. |
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Posted: 3/29/2015 1:34:44 PM EDT
[#9]
Quote HistoryQuoted:
Of course not, presuming the flight load levels are within design specs. They do however account for any proof test loading in calculating overall design life. Strain levels at notches, corners can be substantially higher than average field strain and will lead to crack initiation. A part limited to 6000 cycles at a given strain level would have a much lower life at 125% of that strain level. Proof testing accumulates damage at a higher rate than nominal loads, probably not a lot for a single overload, but it does accumulate somewhat accelerated damage. I dont know enough about mpi to know if the part is not cracked, but very close to crack initiation, if mpi can detect changes in the metals structure. I used to work with various inspectors on critical welds trying to determine what kind of smart flaw could exist within a weld - then do fracture analysis or flaw growth analysis to see if that flaw could potentially propagate and fail within the design life of the part. Our welds were radiographically inspected, dye penetrant inspected, and/or ultrasonically inspected - they all have their limits as to what they will find reliably. Yes, but how many proof rounds do you fire? One. Are you trying to convince me that one 125% overload is going to substantially change the fatigue life that is measured in 6000 plus or minus 1000 rounds? |
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Posted: 3/29/2015 1:48:09 PM EDT
[#10]
Nope, what I'm saying is that the post I quoted wasn't technically accurate. One proof cycle causes more damage than one operational cycle. Without having a lcf curve for c158 or 9310 in the appropriate heat treat its hard to say how much. It could decrease the life by a few hundred cycles, out of the 6000 or so stated as design life.
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Posted: 3/29/2015 2:24:34 PM EDT
[#11]
Quote HistoryQuoted:
Nope, what I'm saying is that the post I quoted wasn't technically accurate. One proof cycle causes more damage than one operational cycle. Without having a lcf curve for c158 or 9310 in the appropriate heat treat its hard to say how much. It could decrease the life by a few hundred cycles, out of the 6000 or so stated as design life. I would say "a few hundred" is a high estimate. You are giving the impression that fatigue life can be calculated to some degree of accuracy. I have seen parts, manufactured, heat treated and finished as close to exactly the same as possible, tested to the same test loads on the same test machine and the measured fatigue lives were 30% to 40% different. (Around 20,000 to 30,000 cycles). I find it hard to believe that you isolate one load over the life of the part and from that, calculate a reduction of around 5% to 10% in the life of that component. I will say that the one cycle was technically and error, but I will stand by the implication that one proof load will not substantially change the published fatigue life of a bolt. |
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Posted: 3/29/2015 3:25:38 PM EDT
[#12]
Yes, 100s of cycles was too pessimistic. My bad.
The overall fatigue life at increased strain levels could easily be reduced by 1/2 give or take. But accumulated damage from a single cycle would not likely materially impact the fatigue life of the part. Still interested though in why proper heat treatment of 9310 is difficult to achieve. |
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Posted: 3/29/2015 8:19:11 PM EDT
[#13]
Quote HistoryQuoted:
Yeah, the High Pressure Test, and the Magnetic Particle Inspection. 
Question fop you guys with the bad out sourced heat treatment: Don't you guys get a heat treat certification sheet for each batch/lot set for treatment? And, how do they mix different manufacturers parts during heat treatment? Quote HistoryQuoted:
Quoted:Stories like this are the prominent reason why most people still prefer C-158 for hard use bolts over 9310. Less likely to go wrong in the manufacturing process, and if a bolt isn't heat treated properly, there is no way of knowing it until the worst possible moment when it fails! Yeah, the High Pressure Test, and the Magnetic Particle Inspection.
Question fop you guys with the bad out sourced heat treatment: Don't you guys get a heat treat certification sheet for each batch/lot set for treatment? And, how do they mix different manufacturers parts during heat treatment? Yes, I rememeber us getting certs for each batch. I can't say for sure if we had our parts in with others, this was awhile ago. One time, I remember reading a material cert at one point that was written ambiguously, well, to me anyway. Say the part was spec'd to 17-4PH Cond H1150 IAW whatever, the cert was something like "minimally meets this requirement" or something like that which I took to mean that it could've been H900 but because it met the min strength it was good to go. Meanwhile, we didn't want something that brittle. I brought it up with management and they were like, "all ahead full." If this happened now, I'd grind shit to a halt to figure out what was going on. |
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Posted: 3/29/2015 8:25:59 PM EDT
[#14]
Quote HistoryQuoted:
Yes, but how many proof rounds do you fire? One. Are you trying to convince me that one 125% overload is going to substantially change the fatigue life that is measured in 6000 plus or minus 1000 rounds? Quote HistoryQuoted:
Quoted:
Of course not, presuming the flight load levels are within design specs. They do however account for any proof test loading in calculating overall design life. Strain levels at notches, corners can be substantially higher than average field strain and will lead to crack initiation. A part limited to 6000 cycles at a given strain level would have a much lower life at 125% of that strain level. Proof testing accumulates damage at a higher rate than nominal loads, probably not a lot for a single overload, but it does accumulate somewhat accelerated damage. I dont know enough about mpi to know if the part is not cracked, but very close to crack initiation, if mpi can detect changes in the metals structure. I used to work with various inspectors on critical welds trying to determine what kind of smart flaw could exist within a weld - then do fracture analysis or flaw growth analysis to see if that flaw could potentially propagate and fail within the design life of the part. Our welds were radiographically inspected, dye penetrant inspected, and/or ultrasonically inspected - they all have their limits as to what they will find reliably. Yes, but how many proof rounds do you fire? One. Are you trying to convince me that one 125% overload is going to substantially change the fatigue life that is measured in 6000 plus or minus 1000 rounds? I'm not a materials guy so this may be a set of dumb questions, how the material response to strain is a function of that loading rate, right? So parts, bolts in this case, can respond in such a way that the high stress rate (more like impulse since there's pressure resolved by area into a force over time) makes them act "stronger" than they are? So does the proof loading of 1.1 or 1.25 take this into account? I guess I'm getting at that I think the effect on cycle life is minimal. The thing Reed may have going for him is a huge pile of data with no failures saying it is statistically very unlikely his part will fail so he forgoes the HPT, just throwing it out there as a thought |
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Posted: 3/29/2015 9:17:56 PM EDT
[#15]
Quote HistoryQuoted:
I'm not a materials guy so this may be a set of dumb questions, how the material response to strain is a function of that loading rate, right? So parts, bolts in this case, can respond in such a way that the high stress rate (more like impulse since there's pressure resolved by area into a force over time) makes them act "stronger" than they are? So does the proof loading of 1.1 or 1.25 take this into account? I guess I'm getting at that I think the effect on cycle life is minimal. The thing Reed may have going for him is a huge pile of data with no failures saying it is statistically very unlikely his part will fail so he forgoes the HPT, just throwing it out there as a thought The way I read the KAC comment is it is just saying that he is sufficiently confident in his suppliers to supply material with no imperfections, and his ability to manufacture parts without imperfections that they will last 5000 to 6000 rounds without the need to proof test them. (and presumably pass the cost savings of not testing along to the customer) If KAC will stand behind there products with enough confidence and offer a lifetime (5000 rounds, or whatever he defines a "bolt life") warranty without proof testing, that is OK with me. In the end, all most people want is a bolt that will last the normal number of rounds, and not fail prematurely. Oh and I made an error. The proof test is a 25% overload, or 125% of the service load. |
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Posted: 3/29/2015 9:41:01 PM EDT
[#16]
Quote HistoryQuoted:
The way I read the KAC comment is it is just saying that he is sufficiently confident in his suppliers to supply material with no imperfections, and his ability to manufacture parts without imperfections that they will last 5000 to 6000 rounds without the need to proof test them. (and presumably pass the cost savings of not testing along to the customer) If KAC will stand behind there products with enough confidence and offer a lifetime (5000 rounds, or whatever he defines a "bolt life") warranty without proof testing, that is OK with me. In the end, all most people want is a bolt that will last the normal number of rounds, and not fail prematurely. Oh and I made an error. The proof test is a 25% overload, or 125% of the service load. Quote HistoryQuoted:
Quoted:
I'm not a materials guy so this may be a set of dumb questions, how the material response to strain is a function of that loading rate, right? So parts, bolts in this case, can respond in such a way that the high stress rate (more like impulse since there's pressure resolved by area into a force over time) makes them act "stronger" than they are? So does the proof loading of 1.1 or 1.25 take this into account? I guess I'm getting at that I think the effect on cycle life is minimal. The thing Reed may have going for him is a huge pile of data with no failures saying it is statistically very unlikely his part will fail so he forgoes the HPT, just throwing it out there as a thought The way I read the KAC comment is it is just saying that he is sufficiently confident in his suppliers to supply material with no imperfections, and his ability to manufacture parts without imperfections that they will last 5000 to 6000 rounds without the need to proof test them. (and presumably pass the cost savings of not testing along to the customer) If KAC will stand behind there products with enough confidence and offer a lifetime (5000 rounds, or whatever he defines a "bolt life") warranty without proof testing, that is OK with me. In the end, all most people want is a bolt that will last the normal number of rounds, and not fail prematurely. Oh and I made an error. The proof test is a 25% overload, or 125% of the service load. With no reports of broken KAC E3 bolts and the round count life of 20-35k, I would say KAC is right about not doing the HPT is better for their bolts. Of course, E3 bolts are different in design and no one know the actual steel material they used, so it is hard to compare to other bolts available. |
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Posted: 3/29/2015 9:49:17 PM EDT
[#17]
Somewhere else someone made this statement:
To perform valid testing, the first requirement would be to perform testing on a large enough statistical sample of rifles so performance can be representative of actual production. Even if this number were 10 rifles, one must acquire the quantity of test ammunition to perform such testing. If the service life is specified at 10,000 rounds, one would have to obtain 100,000 rounds of ammunition to test 10 rifles. To test 50 rifles would require 500,000 rounds of ammunition and to test 100 rifles would require 1 million rounds of ammunition. One can easily see the expense of such testing just in ammunition not to mention the cost of the rifles Not completely true. You don't need half a million rounds to test for fatigue life. You don't even need 10 rifles. Ten or fifteen bolts and one or two barrel extensions and a 5 ton hydraulic press and some hydraulic equipment. The bolt thrust is around 7000 pounds (3.5 tons) for a maximum allowable chamber pressure of 60,000 psi. You hook up the barrel extension to the press with the ram pressing on the bolt face while the lugs are engaged in the extension. Then set up a hydraulic pump to cycle the pressure as necessary to provide 3.5 tons ram thrust at 1 or 2 hertz. You'll reach 6000 cycles in about less than an hour and a half. The model would not be exact as the the load duration would be much shorter in a real rifle, but you could draw some conclusions. If you could get the hydraulics to pulse to peak pressure and relieve it in about a millisecond, the model would be almost exact. But then again some good FE analysis would probably yield just as good estimates and is probably cheaper. |
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Posted: 3/29/2015 10:08:37 PM EDT
[#18]
Quote HistoryBut then again some good FE analysis would probably yield just as good estimates and is probably cheaper. Yup, decent model, accurate load representation, and good materials data from test coupons. |
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Posted: 3/29/2015 10:18:21 PM EDT
[#19]
Quote HistoryQuoted:
With no reports of broken KAC E3 bolts and the round count life of 20-35k, I would say KAC is right about not doing the HPT is better for their bolts. Of course, E3 bolts are different in design and no one know the actual steel material they used, so it is hard to compare to other bolts available. KAC E3 bolts cannot be compared to standard bolts, apples to pears. The KAC design is what the original bolts would have looked like if Melvin Johnson, and Stoner who copied Johnson's bolt, were the engineers they were cracked up to be. The larger radii remove many of the stress concentrations. Big improvement in increasing fatigue life. It has nothing to do with not HPT the bolt. Although, since they changed the extractor, I do wonder why they didn't put the spring parallel to the bore axis |
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Posted: 3/29/2015 10:20:41 PM EDT
[#20]
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Although, since they changed the extractor, I do wonder why they didn't put the spring parallel to the bore axis What do you mean by this? How can the extractor springs be parallel to the bore axis? |
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Posted: 3/30/2015 6:02:25 AM EDT
[#21]
Quote HistoryQuoted:
With no reports of broken KAC E3 bolts and the round count life of 20-35k, I would say KAC is right about not doing the HPT is better for their bolts. Of course, E3 bolts are different in design and no one know the actual steel material they used, so it is hard to compare to other bolts available. Quote HistoryQuoted:
Quoted:
Quoted:
I'm not a materials guy so this may be a set of dumb questions, how the material response to strain is a function of that loading rate, right? So parts, bolts in this case, can respond in such a way that the high stress rate (more like impulse since there's pressure resolved by area into a force over time) makes them act "stronger" than they are? So does the proof loading of 1.1 or 1.25 take this into account? I guess I'm getting at that I think the effect on cycle life is minimal. The thing Reed may have going for him is a huge pile of data with no failures saying it is statistically very unlikely his part will fail so he forgoes the HPT, just throwing it out there as a thought The way I read the KAC comment is it is just saying that he is sufficiently confident in his suppliers to supply material with no imperfections, and his ability to manufacture parts without imperfections that they will last 5000 to 6000 rounds without the need to proof test them. (and presumably pass the cost savings of not testing along to the customer) If KAC will stand behind there products with enough confidence and offer a lifetime (5000 rounds, or whatever he defines a "bolt life") warranty without proof testing, that is OK with me. In the end, all most people want is a bolt that will last the normal number of rounds, and not fail prematurely. Oh and I made an error. The proof test is a 25% overload, or 125% of the service load. With no reports of broken KAC E3 bolts and the round count life of 20-35k, I would say KAC is right about not doing the HPT is better for their bolts. Of course, E3 bolts are different in design and no one know the actual steel material they used, so it is hard to compare to other bolts available. If memory serves me correctly, KAC uses 9310 with their E3. |
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Posted: 3/30/2015 6:52:23 AM EDT
[#22]
Quote HistoryQuoted:
If memory serves me correctly, KAC uses 9310 with their E3. Quote HistoryQuoted:
Quoted:
Quoted:
Quoted:
I'm not a materials guy so this may be a set of dumb questions, how the material response to strain is a function of that loading rate, right? So parts, bolts in this case, can respond in such a way that the high stress rate (more like impulse since there's pressure resolved by area into a force over time) makes them act "stronger" than they are? So does the proof loading of 1.1 or 1.25 take this into account? I guess I'm getting at that I think the effect on cycle life is minimal. The thing Reed may have going for him is a huge pile of data with no failures saying it is statistically very unlikely his part will fail so he forgoes the HPT, just throwing it out there as a thought The way I read the KAC comment is it is just saying that he is sufficiently confident in his suppliers to supply material with no imperfections, and his ability to manufacture parts without imperfections that they will last 5000 to 6000 rounds without the need to proof test them. (and presumably pass the cost savings of not testing along to the customer) If KAC will stand behind there products with enough confidence and offer a lifetime (5000 rounds, or whatever he defines a "bolt life") warranty without proof testing, that is OK with me. In the end, all most people want is a bolt that will last the normal number of rounds, and not fail prematurely. Oh and I made an error. The proof test is a 25% overload, or 125% of the service load. With no reports of broken KAC E3 bolts and the round count life of 20-35k, I would say KAC is right about not doing the HPT is better for their bolts. Of course, E3 bolts are different in design and no one know the actual steel material they used, so it is hard to compare to other bolts available. If memory serves me correctly, KAC uses 9310 with their E3. like I said, what is to be made of range personnel and instructors saying on these forums that non test bolts last longer? |
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Posted: 3/30/2015 7:28:44 AM EDT
[#23]
Quote HistoryQuoted:
If memory serves me correctly, KAC uses 9310 with their E3. Quote HistoryQuoted:
Quoted:
Quoted:
Quoted:
I'm not a materials guy so this may be a set of dumb questions, how the material response to strain is a function of that loading rate, right? So parts, bolts in this case, can respond in such a way that the high stress rate (more like impulse since there's pressure resolved by area into a force over time) makes them act "stronger" than they are? So does the proof loading of 1.1 or 1.25 take this into account? I guess I'm getting at that I think the effect on cycle life is minimal. The thing Reed may have going for him is a huge pile of data with no failures saying it is statistically very unlikely his part will fail so he forgoes the HPT, just throwing it out there as a thought The way I read the KAC comment is it is just saying that he is sufficiently confident in his suppliers to supply material with no imperfections, and his ability to manufacture parts without imperfections that they will last 5000 to 6000 rounds without the need to proof test them. (and presumably pass the cost savings of not testing along to the customer) If KAC will stand behind there products with enough confidence and offer a lifetime (5000 rounds, or whatever he defines a "bolt life") warranty without proof testing, that is OK with me. In the end, all most people want is a bolt that will last the normal number of rounds, and not fail prematurely. Oh and I made an error. The proof test is a 25% overload, or 125% of the service load. With no reports of broken KAC E3 bolts and the round count life of 20-35k, I would say KAC is right about not doing the HPT is better for their bolts. Of course, E3 bolts are different in design and no one know the actual steel material they used, so it is hard to compare to other bolts available. If memory serves me correctly, KAC uses 9310 with their E3. I already asked this on KAC industry forum and never got an actual answer. Some people on the KAC forum said they heard it was AerMet steel, but again, never confirmed. I really don't think we will ever know what steel KAC uses for their E3 bolt unless someone send it to lab or Trey himself can tell us what they use. Some guy on 'that other forum' said 9310, which is where most people got this 9310 information from, but again, it was never confirmed since many people just took his word for it(including me originally). |
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Posted: 3/30/2015 7:30:33 AM EDT
[#24]
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What do you mean by this? How can the extractor springs be parallel to the bore axis? Most other weapon designs place the spring parallel to the bore axis. This allows a longer spring. Most of the AR extractor problems stem from trying to use such a short spring. |
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Posted: 3/30/2015 7:45:22 AM EDT
[#25]
Quote HistoryQuoted:
KAC E3 bolts cannot be compared to standard bolts, apples to pears. The KAC design is what the original bolts would have looked like if Melvin Johnson, and Stoner who copied Johnson's bolt, were the engineers they were cracked up to be. The larger radii remove many of the stress concentrations. Big improvement in increasing fatigue life. It has nothing to do with not HPT the bolt. Although, since they changed the extractor, I do wonder why they didn't put the spring parallel to the bore axis Quote HistoryQuoted:
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With no reports of broken KAC E3 bolts and the round count life of 20-35k, I would say KAC is right about not doing the HPT is better for their bolts. Of course, E3 bolts are different in design and no one know the actual steel material they used, so it is hard to compare to other bolts available. KAC E3 bolts cannot be compared to standard bolts, apples to pears. The KAC design is what the original bolts would have looked like if Melvin Johnson, and Stoner who copied Johnson's bolt, were the engineers they were cracked up to be. The larger radii remove many of the stress concentrations. Big improvement in increasing fatigue life. It has nothing to do with not HPT the bolt. Although, since they changed the extractor, I do wonder why they didn't put the spring parallel to the bore axis Wow.....the KAC fanboyism has reached new depths of insanity with fanatics proclaiming that the company is greater than the originator of the AR platform itself...... Not only that, but then to insinuate that the genious designer and eingineer who is responsible for this site's namesake was "overrated". 
Does this KAC mindless obsession have no shame? Look, fanboy, the AR15 bolt works perfectly with the original AR rifle with which it was designed, and will last tens of thousands of rounds in a rifle system. To suggest that Stoner was somehow subpar in ingenuity to KAC because he did not create a bolt to be compatible with a future change he never foresaw is lunacy. The whole of KAC does not possess 1 / 10th the genius of Stoner, and copies his system for 96% of their rifle. What little changes they do incorporate have been made through standing on the shoulders of giants and observing 50 years of research T&E in the field. KAC is so "innovative", that they use a completely different barrel extension design (proprietary) and had the ability to redesign the bolt anyway they wanted. They could have designed it to use anywhere from 2 to 5 thick beefy lugs (the sig 550 only has 2 AK type lugs and is bullet proof as does the mini). Instead, they mindlesslly copy Stoner's original 7 lug design and only tweak it ever so slightly (does this speak more to their non-ingenuity or to Stoner's genius to still use his 7 lug design?). What's the point of having an entirely new barrel extension and proprietary parts just to keep basically the same 7 lug design that all other ARs have? At that point, they might as well have made it compatible like the LMT enhanced bolt. Going so close just to keep them so far is senseless. KAC fanboyism truly has no bounds!
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Posted: 3/30/2015 8:14:34 AM EDT
[#26]
There's nothing wrong with liking KAC products.
There's nothing wrong with liking a bolt that could last 20k-35k rounds. We all have different preferences, but we are all here b/c we love AR rifles... There is no need to bash on either the standard design or the KAC design, as they both run well and there are reasons to love both 
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Posted: 3/30/2015 8:25:03 AM EDT
[#27]
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Most other weapon designs place the spring parallel to the bore axis. This allows a longer spring. Most of the AR extractor problems stem from trying to use such a short spring. https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTbO3RmsIjrQjpEJxwmAFkp04Bg0qQ_302iAfGZMYpXqrL0q07V7A Quote HistoryQuoted:
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What do you mean by this? How can the extractor springs be parallel to the bore axis? Most other weapon designs place the spring parallel to the bore axis. This allows a longer spring. Most of the AR extractor problems stem from trying to use such a short spring. https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTbO3RmsIjrQjpEJxwmAFkp04Bg0qQ_302iAfGZMYpXqrL0q07V7A Interesting, I never realized this even though my FAL and AK both use the parallel design. Seems like all the newer design that uses the multi lug bolt will have the perpendicular spring, for example the AUG, SCAR, G36 |
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Posted: 3/30/2015 8:59:23 AM EDT
[#28]
Quote HistoryQuoted:
KAC fanboyism truly has no bounds! Quote HistoryQuoted:
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With no reports of broken KAC E3 bolts and the round count life of 20-35k, I would say KAC is right about not doing the HPT is better for their bolts. Of course, E3 bolts are different in design and no one know the actual steel material they used, so it is hard to compare to other bolts available. KAC E3 bolts cannot be compared to standard bolts, apples to pears. The KAC design is what the original bolts would have looked like if Melvin Johnson, and Stoner who copied Johnson's bolt, were the engineers they were cracked up to be. The larger radii remove many of the stress concentrations. Big improvement in increasing fatigue life. It has nothing to do with not HPT the bolt. Although, since they changed the extractor, I do wonder why they didn't put the spring parallel to the bore axis KAC fanboyism truly has no bounds! I'm far from a KAC fan boy. But BCM ...
Anyway. The main advantage that KAC has over everyone IS the E3, IMO. Has there ever been a report of a broken E3? None that I have ever read about... But, there isn't near as many E3's compared to standard bolts out there being used. |
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Posted: 3/30/2015 10:04:05 AM EDT
[#29]
Quote HistoryQuoted:
Wow.....the KAC fanboyism has reached new depths of insanity with fanatics proclaiming that the company is greater than the originator of the AR platform itself [Note to self, never insult god] Does this KAC mindless obsession have no shame? Look, fanboy, the AR15 bolt works perfectly with the original AR rifle with which it was designed, and will last tens of thousands of rounds in a rifle system. To suggest that Stoner . . . . I'm a fanboy, didn't realize that...Up until two minutes before I posted that comment, I didn't realize that it was Knight's Armament was the company that made those round lug bolts. I had seen those bolts before and noted that that was a simple and quick way to improve the fatigue life of a part that should last longer than it does. I never thought much more about it as it was proprietary, and that usually = expensive. The reason the Johnson M-1941 bolt was shaped the way it is, is because it is easier and faster to manufacture than most other designs, especially the Garand bolt. The problem is that when you reduce the size, the stress goes up by four times. (The stress is proportional to the area or the size dimension squared.) The fact that nobody though that fatigue was going to be a problem with a bolt head covered with sharp corners and included angles and loaded to a point very close to the plastic range shows me something. They should have suspected they were skirting a fatigue problem when they had to use such a high strength steel when most people at the time were doing fine with 8620 or 14XX. To manufacture an M16 bolt with large radii would not be any more difficult to do than to do it with sharp corners. And back in the days before you could do everything on a machining center, I would think that large radii would have been easier on the tooling. I apologize to all the Stoner fan-boys, if my views have insulted. |
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Posted: 3/30/2015 11:09:00 AM EDT
[#30]
Quote HistoryQuoted:
Wow.....the KAC fanboyism has reached new depths of insanity with fanatics proclaiming that the company is greater than the originator of the AR platform itself...... Not only that, but then to insinuate that the genious designer and eingineer who is responsible for this site's namesake was "overrated".
Does this KAC mindless obsession have no shame? Look, fanboy, the AR15 bolt works perfectly with the original AR rifle with which it was designed, and will last tens of thousands of rounds in a rifle system. To suggest that Stoner was somehow subpar in ingenuity to KAC because he did not create a bolt to be compatible with a future change he never foresaw is lunacy. The whole of KAC does not possess 1 / 10th the genius of Stoner, and copies his system for 96% of their rifle. What little changes they do incorporate have been made through standing on the shoulders of giants and observing 50 years of research T&E in the field. KAC is so "innovative", that they use a completely different barrel extension design (proprietary) and had the ability to redesign the bolt anyway they wanted. They could have designed it to use anywhere from 2 to 5 thick beefy lugs (the sig 550 only has 2 AK type lugs and is bullet proof as does the mini). Instead, they mindlesslly copy Stoner's original 7 lug design and only tweak it ever so slightly (does this speak more to their non-ingenuity or to Stoner's genius to still use his 7 lug design?). What's the point of having an entirely new barrel extension and proprietary parts just to keep basically the same 7 lug design that all other ARs have? At that point, they might as well have made it compatible like the LMT enhanced bolt. Going so close just to keep them so far is senseless. KAC fanboyism truly has no bounds! Quote HistoryQuoted:
Quoted:
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With no reports of broken KAC E3 bolts and the round count life of 20-35k, I would say KAC is right about not doing the HPT is better for their bolts. Of course, E3 bolts are different in design and no one know the actual steel material they used, so it is hard to compare to other bolts available. KAC E3 bolts cannot be compared to standard bolts, apples to pears. The KAC design is what the original bolts would have looked like if Melvin Johnson, and Stoner who copied Johnson's bolt, were the engineers they were cracked up to be. The larger radii remove many of the stress concentrations. Big improvement in increasing fatigue life. It has nothing to do with not HPT the bolt. Although, since they changed the extractor, I do wonder why they didn't put the spring parallel to the bore axis Wow.....the KAC fanboyism has reached new depths of insanity with fanatics proclaiming that the company is greater than the originator of the AR platform itself...... Not only that, but then to insinuate that the genious designer and eingineer who is responsible for this site's namesake was "overrated".
Does this KAC mindless obsession have no shame? Look, fanboy, the AR15 bolt works perfectly with the original AR rifle with which it was designed, and will last tens of thousands of rounds in a rifle system. To suggest that Stoner was somehow subpar in ingenuity to KAC because he did not create a bolt to be compatible with a future change he never foresaw is lunacy. The whole of KAC does not possess 1 / 10th the genius of Stoner, and copies his system for 96% of their rifle. What little changes they do incorporate have been made through standing on the shoulders of giants and observing 50 years of research T&E in the field. KAC is so "innovative", that they use a completely different barrel extension design (proprietary) and had the ability to redesign the bolt anyway they wanted. They could have designed it to use anywhere from 2 to 5 thick beefy lugs (the sig 550 only has 2 AK type lugs and is bullet proof as does the mini). Instead, they mindlesslly copy Stoner's original 7 lug design and only tweak it ever so slightly (does this speak more to their non-ingenuity or to Stoner's genius to still use his 7 lug design?). What's the point of having an entirely new barrel extension and proprietary parts just to keep basically the same 7 lug design that all other ARs have? At that point, they might as well have made it compatible like the LMT enhanced bolt. Going so close just to keep them so far is senseless. KAC fanboyism truly has no bounds! Speaking of bolts, have you ever seen or heard of an enhanced LMT breaking? I have not, they essentially fixed every issue with the M4 and Mk18 with a BCG that is 100% compatible with the M4 and MK18. That to me speaks more genious than the KAC. The LMT E-BCG can also be had for the price of a E3 bolt. |
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Posted: 3/30/2015 11:11:09 AM EDT
[#31]
Quote HistoryQuoted:
I'm a fanboy, didn't realize that...Up until two minutes before I posted that comment, I didn't realize that it was Knight's Armament was the company that made those round lug bolts. I had seen those bolts before and noted that that was a simple and quick way to improve the fatigue life of a part that should last longer than it does. I never thought much more about it as it was proprietary, and that usually = expensive. The reason the Johnson M-1941 bolt was shaped the way it is, is because it is easier and faster to manufacture than most other designs, especially the Garand bolt. The problem is that when you reduce the size, the stress goes up by four times. (The stress is proportional to the area or the size dimension squared.) The fact that nobody though that fatigue was going to be a problem with a bolt head covered with sharp corners and included angles and loaded to a point very close to the plastic range shows me something. They should have suspected they were skirting a fatigue problem when they had to use such a high strength steel when most people at the time were doing fine with 8620 or 14XX. To manufacture an M16 bolt with large radii would not be any more difficult to do than to do it with sharp corners. And back in the days before you could do everything on a machining center, I would think that large radii would have been easier on the tooling. I apologize to all the Stoner fan-boys, if my views have insulted. Quote HistoryQuoted:
Quoted:
Wow.....the KAC fanboyism has reached new depths of insanity with fanatics proclaiming that the company is greater than the originator of the AR platform itself [Note to self, never insult god] Does this KAC mindless obsession have no shame? Look, fanboy, the AR15 bolt works perfectly with the original AR rifle with which it was designed, and will last tens of thousands of rounds in a rifle system. To suggest that Stoner . . . . I'm a fanboy, didn't realize that...Up until two minutes before I posted that comment, I didn't realize that it was Knight's Armament was the company that made those round lug bolts. I had seen those bolts before and noted that that was a simple and quick way to improve the fatigue life of a part that should last longer than it does. I never thought much more about it as it was proprietary, and that usually = expensive. The reason the Johnson M-1941 bolt was shaped the way it is, is because it is easier and faster to manufacture than most other designs, especially the Garand bolt. The problem is that when you reduce the size, the stress goes up by four times. (The stress is proportional to the area or the size dimension squared.) The fact that nobody though that fatigue was going to be a problem with a bolt head covered with sharp corners and included angles and loaded to a point very close to the plastic range shows me something. They should have suspected they were skirting a fatigue problem when they had to use such a high strength steel when most people at the time were doing fine with 8620 or 14XX. To manufacture an M16 bolt with large radii would not be any more difficult to do than to do it with sharp corners. And back in the days before you could do everything on a machining center, I would think that large radii would have been easier on the tooling. I apologize to all the Stoner fan-boys, if my views have insulted. Yet breaking bolts was not an issue with the M16. It was not till the M4 and MK18 that bolts started breaking in the 10,000 round range. |
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Posted: 3/30/2015 11:34:35 AM EDT
[#32]
Quote HistoryQuoted: Yet breaking bolts was not an issue with the M16. It was not till the M4 and MK18 that bolts started breaking in the 10,000 round range. Quote HistoryQuoted: Quoted: Quoted: Wow.....the KAC fanboyism has reached new depths of insanity with fanatics proclaiming that the company is greater than the originator of the AR platform itself [Note to self, never insult god] Does this KAC mindless obsession have no shame? Look, fanboy, the AR15 bolt works perfectly with the original AR rifle with which it was designed, and will last tens of thousands of rounds in a rifle system. To suggest that Stoner . . . . I'm a fanboy, didn't realize that...Up until two minutes before I posted that comment, I didn't realize that it was Knight's Armament was the company that made those round lug bolts. I had seen those bolts before and noted that that was a simple and quick way to improve the fatigue life of a part that should last longer than it does. I never thought much more about it as it was proprietary, and that usually = expensive. The reason the Johnson M-1941 bolt was shaped the way it is, is because it is easier and faster to manufacture than most other designs, especially the Garand bolt. The problem is that when you reduce the size, the stress goes up by four times. (The stress is proportional to the area or the size dimension squared.) The fact that nobody though that fatigue was going to be a problem with a bolt head covered with sharp corners and included angles and loaded to a point very close to the plastic range shows me something. They should have suspected they were skirting a fatigue problem when they had to use such a high strength steel when most people at the time were doing fine with 8620 or 14XX. To manufacture an M16 bolt with large radii would not be any more difficult to do than to do it with sharp corners. And back in the days before you could do everything on a machining center, I would think that large radii would have been easier on the tooling. I apologize to all the Stoner fan-boys, if my views have insulted. Yet breaking bolts was not an issue with the M16. It was not till the M4 and MK18 that bolts started breaking in the 10,000 round range. They often times break earlier than the 10,000 rd mark. |
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Posted: 3/30/2015 12:01:01 PM EDT
[#33]
Something will have to be done by the military to extend the life of bolts in M16s and M4s with the new M855A1 ammo becoming more common.
According to the Army, some bolt cracking is being observed at 6,000 rounds under full auto use with the higher pressure M855A1 ammo,. |
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Posted: 3/30/2015 12:20:59 PM EDT
[#34]
Quote HistoryQuoted:
They often times very occasionally break earlier than the 10,000 rd mark. Quote HistoryQuoted:
Quoted:
Quoted:
Quoted:
Wow.....the KAC fanboyism has reached new depths of insanity with fanatics proclaiming that the company is greater than the originator of the AR platform itself [Note to self, never insult god] Does this KAC mindless obsession have no shame? Look, fanboy, the AR15 bolt works perfectly with the original AR rifle with which it was designed, and will last tens of thousands of rounds in a rifle system. To suggest that Stoner . . . . I'm a fanboy, didn't realize that...Up until two minutes before I posted that comment, I didn't realize that it was Knight's Armament was the company that made those round lug bolts. I had seen those bolts before and noted that that was a simple and quick way to improve the fatigue life of a part that should last longer than it does. I never thought much more about it as it was proprietary, and that usually = expensive. The reason the Johnson M-1941 bolt was shaped the way it is, is because it is easier and faster to manufacture than most other designs, especially the Garand bolt. The problem is that when you reduce the size, the stress goes up by four times. (The stress is proportional to the area or the size dimension squared.) The fact that nobody though that fatigue was going to be a problem with a bolt head covered with sharp corners and included angles and loaded to a point very close to the plastic range shows me something. They should have suspected they were skirting a fatigue problem when they had to use such a high strength steel when most people at the time were doing fine with 8620 or 14XX. To manufacture an M16 bolt with large radii would not be any more difficult to do than to do it with sharp corners. And back in the days before you could do everything on a machining center, I would think that large radii would have been easier on the tooling. I apologize to all the Stoner fan-boys, if my views have insulted. Yet breaking bolts was not an issue with the M16. It was not till the M4 and MK18 that bolts started breaking in the 10,000 round range. They often times very occasionally break earlier than the 10,000 rd mark. There, fixed it for you! Seriously, do you know how many 16" carbine variants are out there? They are the single most common type of AR in existence. Many people have shot these carbine gas guns for multiple thousands of rounds past what the majority of "experts" on this board would advise, and they still run fine. I guess they don't know that they are supposed to fail on them. How often do we even hear about broken bolts on this board, where people "know" better? You don't hear about it all that often, and you know how the rule goes. For every complaint you hear about, there are 10 more that served their user just fine that you don't hear about! Now the carbines are harder on bolts, and if there is an issue with a bolt (heat treat, crack, etc) it will show itself much earlier and they can fail in under 10k rounds, but that is hardly the norm and it usually takes a very harsh firing schedule to do so. |
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Posted: 3/30/2015 12:25:04 PM EDT
[#35]
Quote HistoryQuoted:
Speaking of bolts, have you ever seen or heard of an enhanced LMT breaking? I have not, they essentially fixed every issue with the M4 and Mk18 with a BCG that is 100% compatible with the M4 and MK18. That to me speaks more genious than the KAC. The LMT E-BCG can also be had for the price of a E3 bolt. Quote HistoryQuoted:
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Quoted:
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With no reports of broken KAC E3 bolts and the round count life of 20-35k, I would say KAC is right about not doing the HPT is better for their bolts. Of course, E3 bolts are different in design and no one know the actual steel material they used, so it is hard to compare to other bolts available. KAC E3 bolts cannot be compared to standard bolts, apples to pears. The KAC design is what the original bolts would have looked like if Melvin Johnson, and Stoner who copied Johnson's bolt, were the engineers they were cracked up to be. The larger radii remove many of the stress concentrations. Big improvement in increasing fatigue life. It has nothing to do with not HPT the bolt. Although, since they changed the extractor, I do wonder why they didn't put the spring parallel to the bore axis Wow.....the KAC fanboyism has reached new depths of insanity with fanatics proclaiming that the company is greater than the originator of the AR platform itself...... Not only that, but then to insinuate that the genious designer and eingineer who is responsible for this site's namesake was "overrated".
Does this KAC mindless obsession have no shame? Look, fanboy, the AR15 bolt works perfectly with the original AR rifle with which it was designed, and will last tens of thousands of rounds in a rifle system. To suggest that Stoner was somehow subpar in ingenuity to KAC because he did not create a bolt to be compatible with a future change he never foresaw is lunacy. The whole of KAC does not possess 1 / 10th the genius of Stoner, and copies his system for 96% of their rifle. What little changes they do incorporate have been made through standing on the shoulders of giants and observing 50 years of research T&E in the field. KAC is so "innovative", that they use a completely different barrel extension design (proprietary) and had the ability to redesign the bolt anyway they wanted. They could have designed it to use anywhere from 2 to 5 thick beefy lugs (the sig 550 only has 2 AK type lugs and is bullet proof as does the mini). Instead, they mindlesslly copy Stoner's original 7 lug design and only tweak it ever so slightly (does this speak more to their non-ingenuity or to Stoner's genius to still use his 7 lug design?). What's the point of having an entirely new barrel extension and proprietary parts just to keep basically the same 7 lug design that all other ARs have? At that point, they might as well have made it compatible like the LMT enhanced bolt. Going so close just to keep them so far is senseless. KAC fanboyism truly has no bounds! Speaking of bolts, have you ever seen or heard of an enhanced LMT breaking? I have not, they essentially fixed every issue with the M4 and Mk18 with a BCG that is 100% compatible with the M4 and MK18. That to me speaks more genious than the KAC. The LMT E-BCG can also be had for the price of a E3 bolt. This. It's not as cool or exclusive to just buy a drop in part though. It's cooler to have some "high end" $2k proprietary rifle, otherwise it would be too common for bragging rights! |
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Posted: 3/30/2015 12:31:58 PM EDT
[#36]
Quote HistoryQuoted: There, fixed it for you! Seriously, do you know how many 16" carbine variants are out there? They are the single most common type of AR in existence. Many people have shot these carbine gas guns for multiple thousands of rounds past what the majority of "experts" on this board would advise, and they still run fine. I guess they don't know that they are supposed to fail on them. How often do we even hear about broken bolts on this board, where people "know" better? You don't hear about it all that often, and you know how the rule goes. For every complaint you hear about, there are 10 more that served their user just fine that you don't hear about! Now the carbines are harder on bolts, and if there is an issue with a bolt (heat treat, crack, etc) it will show itself much earlier and they can fail in under 10k rounds, but that is hardly the norm and it usually takes a very harsh firing schedule to do so. Quote HistoryQuoted: Quoted: SNIPThey often times very occasionally break earlier than the 10,000 rd mark. There, fixed it for you! Seriously, do you know how many 16" carbine variants are out there? They are the single most common type of AR in existence. Many people have shot these carbine gas guns for multiple thousands of rounds past what the majority of "experts" on this board would advise, and they still run fine. I guess they don't know that they are supposed to fail on them. How often do we even hear about broken bolts on this board, where people "know" better? You don't hear about it all that often, and you know how the rule goes. For every complaint you hear about, there are 10 more that served their user just fine that you don't hear about! Now the carbines are harder on bolts, and if there is an issue with a bolt (heat treat, crack, etc) it will show itself much earlier and they can fail in under 10k rounds, but that is hardly the norm and it usually takes a very harsh firing schedule to do so. SOCOM report used the words MOST. http://www.dtic.mil/ndia/2006smallarms/taylor.pdf Refer to page 44. ETA: For clarity, I was referring to cracks, not full breakage. Once a crack is found I would discontinue use unless it's just a range toy and you want to see how long it takes a lug to fail. |
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Posted: 3/30/2015 12:32:12 PM EDT
[#37]
Quote HistoryQuoted:Look, fanboy, the AR15 bolt works perfectly with the original AR rifle with which it was designed, and will last tens of thousands of rounds in a rifle system. To suggest that Stoner was somehow subpar in ingenuity to KAC because he did not create a bolt to be compatible with a future change he never foresaw is lunacy. The whole of KAC does not possess 1 / 10th the genius of Stoner, and copies his system for 96% of their rifle. What little changes they do incorporate have been made through standing on the shoulders of giants and observing 50 years of research T&E in the field.
KAC is so "innovative", that they use a completely different barrel extension design (proprietary) and had the ability to redesign the bolt anyway they wanted. They could have designed it to use anywhere from 2 to 5 thick beefy lugs (the sig 550 only has 2 AK type lugs and is bullet proof as does the mini). Instead, they mindlesslly copy Stoner's original 7 lug design and only tweak it ever so slightly (does this speak more to their non-ingenuity or to Stoner's genius to still use his 7 lug design?). What's the point of having an entirely new barrel extension and proprietary parts just to keep basically the same 7 lug design that all other ARs have? At that point, they might as well have made it compatible like the LMT enhanced bolt. Going so close just to keep them so far is senseless. Uhh... you know KAC was where Stoner last worked before his death, right? If anything, you're claiming Stoner wasn't as innovative as Stoner, and that Stoner should have just stuck with his original Stoner design... |
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Posted: 3/30/2015 12:35:51 PM EDT
[#38]
Quote HistoryQuoted:
SOCOM report used the words MOST. http://www.dtic.mil/ndia/2006smallarms/taylor.pdf Refer to page 44. ETA: For clarity, I was referring to cracks, not full breakage. Once a crack is found I would discontinue use unless it's just a range toy and you want to see how long it takes a lug to fail. Quote HistoryQuoted:
Quoted:
Quoted:
SNIPThey often times very occasionally break earlier than the 10,000 rd mark. There, fixed it for you! Seriously, do you know how many 16" carbine variants are out there? They are the single most common type of AR in existence. Many people have shot these carbine gas guns for multiple thousands of rounds past what the majority of "experts" on this board would advise, and they still run fine. I guess they don't know that they are supposed to fail on them. How often do we even hear about broken bolts on this board, where people "know" better? You don't hear about it all that often, and you know how the rule goes. For every complaint you hear about, there are 10 more that served their user just fine that you don't hear about! Now the carbines are harder on bolts, and if there is an issue with a bolt (heat treat, crack, etc) it will show itself much earlier and they can fail in under 10k rounds, but that is hardly the norm and it usually takes a very harsh firing schedule to do so. SOCOM report used the words MOST. http://www.dtic.mil/ndia/2006smallarms/taylor.pdf Refer to page 44. ETA: For clarity, I was referring to cracks, not full breakage. Once a crack is found I would discontinue use unless it's just a range toy and you want to see how long it takes a lug to fail. According to the info in the Mk18 thread that was revised to 10,000 rounds replacement on bolts. That is 9 year old data at this point. |
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Posted: 3/30/2015 12:41:53 PM EDT
[#39]
Quote HistoryQuoted:
According to the info in the Mk18 thread that was revised to 10,000 rounds replacement on bolts. That is 9 year old data at this point. Quote HistoryQuoted:
According to the info in the Mk18 thread that was revised to 10,000 rounds replacement on bolts. That is 9 year old data at this point. And for guns undergoing harsh full auto firing schedules. Semi auto, even rapid fire, doesn't impart nearly as much stress. Quoted:
Quoted:Look, fanboy, the AR15 bolt works perfectly with the original AR rifle with which it was designed, and will last tens of thousands of rounds in a rifle system. To suggest that Stoner was somehow subpar in ingenuity to KAC because he did not create a bolt to be compatible with a future change he never foresaw is lunacy. The whole of KAC does not possess 1 / 10th the genius of Stoner, and copies his system for 96% of their rifle. What little changes they do incorporate have been made through standing on the shoulders of giants and observing 50 years of research T&E in the field.
KAC is so "innovative", that they use a completely different barrel extension design (proprietary) and had the ability to redesign the bolt anyway they wanted. They could have designed it to use anywhere from 2 to 5 thick beefy lugs (the sig 550 only has 2 AK type lugs and is bullet proof as does the mini). Instead, they mindlesslly copy Stoner's original 7 lug design and only tweak it ever so slightly (does this speak more to their non-ingenuity or to Stoner's genius to still use his 7 lug design?). What's the point of having an entirely new barrel extension and proprietary parts just to keep basically the same 7 lug design that all other ARs have? At that point, they might as well have made it compatible like the LMT enhanced bolt. Going so close just to keep them so far is senseless. Uhh... you know KAC was where Stoner last worked before his death, right? If anything, you're claiming Stoner wasn't as innovative as Stoner, and that Stoner should have just stuck with his original Stoner design... Stoner had no part in developing the SR-15, and up untill the mid 2000s the only AR types they sold were M4 style clones. Though it was odd for that posterer to bash Stoner when he did work at the rifle company he loves so much. |
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Posted: 3/30/2015 12:49:01 PM EDT
[#40]
Quote HistoryQuoted: And for guns undergoing harsh full auto firing schedules. Semi auto, even rapid fire, doesn't impart nearly as much stress. Stoner had no part in developing the SR-15, and up untill the mid 2000s the only AR types they sold were M4 style clones. Though it was odd for that posterer to bash Stoner when he did work at the rifle company he loves so much. Quote HistoryQuoted: Quoted: According to the info in the Mk18 thread that was revised to 10,000 rounds replacement on bolts. That is 9 year old data at this point. And for guns undergoing harsh full auto firing schedules. Semi auto, even rapid fire, doesn't impart nearly as much stress. Quoted: Quoted:Look, fanboy, the AR15 bolt works perfectly with the original AR rifle with which it was designed, and will last tens of thousands of rounds in a rifle system. To suggest that Stoner was somehow subpar in ingenuity to KAC because he did not create a bolt to be compatible with a future change he never foresaw is lunacy. The whole of KAC does not possess 1 / 10th the genius of Stoner, and copies his system for 96% of their rifle. What little changes they do incorporate have been made through standing on the shoulders of giants and observing 50 years of research T&E in the field. KAC is so "innovative", that they use a completely different barrel extension design (proprietary) and had the ability to redesign the bolt anyway they wanted. They could have designed it to use anywhere from 2 to 5 thick beefy lugs (the sig 550 only has 2 AK type lugs and is bullet proof as does the mini). Instead, they mindlesslly copy Stoner's original 7 lug design and only tweak it ever so slightly (does this speak more to their non-ingenuity or to Stoner's genius to still use his 7 lug design?). What's the point of having an entirely new barrel extension and proprietary parts just to keep basically the same 7 lug design that all other ARs have? At that point, they might as well have made it compatible like the LMT enhanced bolt. Going so close just to keep them so far is senseless. Uhh... you know KAC was where Stoner last worked before his death, right? If anything, you're claiming Stoner wasn't as innovative as Stoner, and that Stoner should have just stuck with his original Stoner design... Stoner had no part in developing the SR-15, and up untill the mid 2000s the only AR types they sold were M4 style clones. Though it was odd for that posterer to bash Stoner when he did work at the rifle company he loves so much. Got a link to the MK18 thread? I haven't read the revision yet. My semi auto imparts just as much stress as a machinegun  http://youtu.be/-kKWMqt6TnQ I know on my SOTF deployment many of the MK18's already had their bolts replaced with LWRC ACB's. |
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Posted: 3/30/2015 1:31:35 PM EDT
[#41]
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There, fixed it for you! Seriously, do you know how many 16" carbine variants are out there? They are the single most common type of AR in existence. Many people have shot these carbine gas guns for multiple thousands of rounds past what the majority of "experts" on this board would advise, and they still run fine. I guess they don't know that they are supposed to fail on them. How often do we even hear about broken bolts on this board, where people "know" better? You don't hear about it all that often, and you know how the rule goes. For every complaint you hear about, there are 10 more that served their user just fine that you don't hear about! Now the carbines are harder on bolts, and if there is an issue with a bolt (heat treat, crack, etc) it will show itself much earlier and they can fail in under 10k rounds, but that is hardly the norm and it usually takes a very harsh firing schedule to do so. Quote HistoryQuoted:
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Wow.....the KAC fanboyism has reached new depths of insanity with fanatics proclaiming that the company is greater than the originator of the AR platform itself [Note to self, never insult god] Does this KAC mindless obsession have no shame? Look, fanboy, the AR15 bolt works perfectly with the original AR rifle with which it was designed, and will last tens of thousands of rounds in a rifle system. To suggest that Stoner . . . . I'm a fanboy, didn't realize that...Up until two minutes before I posted that comment, I didn't realize that it was Knight's Armament was the company that made those round lug bolts. I had seen those bolts before and noted that that was a simple and quick way to improve the fatigue life of a part that should last longer than it does. I never thought much more about it as it was proprietary, and that usually = expensive. The reason the Johnson M-1941 bolt was shaped the way it is, is because it is easier and faster to manufacture than most other designs, especially the Garand bolt. The problem is that when you reduce the size, the stress goes up by four times. (The stress is proportional to the area or the size dimension squared.) The fact that nobody though that fatigue was going to be a problem with a bolt head covered with sharp corners and included angles and loaded to a point very close to the plastic range shows me something. They should have suspected they were skirting a fatigue problem when they had to use such a high strength steel when most people at the time were doing fine with 8620 or 14XX. To manufacture an M16 bolt with large radii would not be any more difficult to do than to do it with sharp corners. And back in the days before you could do everything on a machining center, I would think that large radii would have been easier on the tooling. I apologize to all the Stoner fan-boys, if my views have insulted. Yet breaking bolts was not an issue with the M16. It was not till the M4 and MK18 that bolts started breaking in the 10,000 round range. They often times very occasionally break earlier than the 10,000 rd mark. There, fixed it for you! Seriously, do you know how many 16" carbine variants are out there? They are the single most common type of AR in existence. Many people have shot these carbine gas guns for multiple thousands of rounds past what the majority of "experts" on this board would advise, and they still run fine. I guess they don't know that they are supposed to fail on them. How often do we even hear about broken bolts on this board, where people "know" better? You don't hear about it all that often, and you know how the rule goes. For every complaint you hear about, there are 10 more that served their user just fine that you don't hear about! Now the carbines are harder on bolts, and if there is an issue with a bolt (heat treat, crack, etc) it will show itself much earlier and they can fail in under 10k rounds, but that is hardly the norm and it usually takes a very harsh firing schedule to do so. I would wager a lot of money that >95% of civilian AR's have seen less than 5,000 rounds. Also, many of the bolt and barrel life figures refer to military guns that see some auto fire. A rifle that gets babied will obviously last longer. The truth is that Stoner did not redesign the bolt for the higher pressure .223 after the switch was made from the .222. Every move toward shorter gas systems and higher pressure rounds further cuts into what was a pretty good margin of safety built into a 20" .222 Rem rifle. |
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Posted: 3/30/2015 1:35:34 PM EDT
[#42]
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Got a link to the MK18 thread? I haven't read the revision yet. My semi auto imparts just as much stress as a machinegun
http://youtu.be/-kKWMqt6TnQ I know on my SOTF deployment many of the MK18's already had their bolts replaced with LWRC ACB's. Quote HistoryQuoted:
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According to the info in the Mk18 thread that was revised to 10,000 rounds replacement on bolts. That is 9 year old data at this point. And for guns undergoing harsh full auto firing schedules. Semi auto, even rapid fire, doesn't impart nearly as much stress. Quoted:
Quoted:Look, fanboy, the AR15 bolt works perfectly with the original AR rifle with which it was designed, and will last tens of thousands of rounds in a rifle system. To suggest that Stoner was somehow subpar in ingenuity to KAC because he did not create a bolt to be compatible with a future change he never foresaw is lunacy. The whole of KAC does not possess 1 / 10th the genius of Stoner, and copies his system for 96% of their rifle. What little changes they do incorporate have been made through standing on the shoulders of giants and observing 50 years of research T&E in the field.
KAC is so "innovative", that they use a completely different barrel extension design (proprietary) and had the ability to redesign the bolt anyway they wanted. They could have designed it to use anywhere from 2 to 5 thick beefy lugs (the sig 550 only has 2 AK type lugs and is bullet proof as does the mini). Instead, they mindlesslly copy Stoner's original 7 lug design and only tweak it ever so slightly (does this speak more to their non-ingenuity or to Stoner's genius to still use his 7 lug design?). What's the point of having an entirely new barrel extension and proprietary parts just to keep basically the same 7 lug design that all other ARs have? At that point, they might as well have made it compatible like the LMT enhanced bolt. Going so close just to keep them so far is senseless. Uhh... you know KAC was where Stoner last worked before his death, right? If anything, you're claiming Stoner wasn't as innovative as Stoner, and that Stoner should have just stuck with his original Stoner design... Stoner had no part in developing the SR-15, and up untill the mid 2000s the only AR types they sold were M4 style clones. Though it was odd for that posterer to bash Stoner when he did work at the rifle company he loves so much. Got a link to the MK18 thread? I haven't read the revision yet. My semi auto imparts just as much stress as a machinegun
http://youtu.be/-kKWMqt6TnQ I know on my SOTF deployment many of the MK18's already had their bolts replaced with LWRC ACB's. I think he's referring to page 472, info posted by Combat_Diver. |
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Posted: 3/30/2015 1:38:54 PM EDT
[#43]
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I would wager a lot of money that >95% of civilian AR's have seen less than 5,000 rounds. Also, many of the bolt and barrel life figures refer to military guns that see some auto fire. A rifle that gets babied will obviously last longer. The truth is that Stoner did not redesign the bolt for the higher pressure .223 after the switch was made from the .222. Every move toward shorter gas systems and higher pressure rounds further cuts into what was a pretty good margin of safety built into a 20" .222 Rem rifle. Stoner actually designed the bolt for 7.62x51 before he ever did for .222, he just scaled it down. Even once 5.56 was adopted, bolt failure was not a problem for the M16 until carbine variants become prolific. |
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Posted: 3/30/2015 1:45:14 PM EDT
[#44]
Thats the one.
http://www.ar15.com/forums/t_3_118/641240_Official_Mk_18_and_CQBR_Photo_and_Discussion_Thread.html&page=472 According to CD it now has a 10,000 round replacement cycle. I am also curious how you got a LWRC ACB? They stated back when the M6IC was struggling to launch that they would come with standard bolts due to troubles producing the ACB. They to this day have no released any more ACB's in 5.56, just 6.8. LWRC ACB issues There were issues on the ACB1 They stopped fielding it and went to milspec bolts until the revision was done to the ACB. The ACB2 will be fielded soon, I have no dates. I'm running a Milspec in my SBR and the ACB1 in my SPR... both work fine. Your Milspec bolts will work fine. Just realize that the extractor will wear just like it would in a DI gun, and might need replacement between 5-8k rnds. The ACB will just last longer. 3 years later and still no ACB2. When one of the main guys for a company says their bolt has issues.......well I wouldn't want to be issued one. |
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Posted: 3/30/2015 2:01:15 PM EDT
[#45]
Quote HistoryQuoted: Thats the one. http://www.ar15.com/forums/t_3_118/641240_Official_Mk_18_and_CQBR_Photo_and_Discussion_Thread.html&page=472 According to CD it now has a 10,000 round replacement cycle. I am also curious how you got a LWRC ACB? They stated back when the M6IC was struggling to launch that they would come with standard bolts due to troubles producing the ACB. They to this day have no released any more ACB's in 5.56, just 6.8. I don't have any background on when they were acquired. I was issued an M4, but several of the operators I was with had MK18 uppers and the bolts had been replaced with the ACB's. I am not aware how many the armory still had available or what the rules were regarding replacement. They were put in by the armorer though and ordered through the supply system. It was more than just a single guy who brought his own bolt. The guys who had them didn't know the difference. I recognized them from the LW S2 marking on the lobster tail style extractor. |
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Posted: 3/30/2015 2:06:47 PM EDT
[#46]
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I don't have any background on when they were acquired. I was issued an M4, but several of the operators I was with had MK18 uppers and the bolts had been replaced with the ACB's. I am not aware how many the armory still had available or what the rules were regarding replacement. They were put in by the armorer though and ordered through the supply system. It was more than just a single guy who brought his own bolt. The guys who had them didn't know the difference. I recognized them from the LW S2 marking on the lobster tail style extractor. Quote HistoryQuoted:
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Thats the one. http://www.ar15.com/forums/t_3_118/641240_Official_Mk_18_and_CQBR_Photo_and_Discussion_Thread.html&page=472 According to CD it now has a 10,000 round replacement cycle. I am also curious how you got a LWRC ACB? They stated back when the M6IC was struggling to launch that they would come with standard bolts due to troubles producing the ACB. They to this day have no released any more ACB's in 5.56, just 6.8. I don't have any background on when they were acquired. I was issued an M4, but several of the operators I was with had MK18 uppers and the bolts had been replaced with the ACB's. I am not aware how many the armory still had available or what the rules were regarding replacement. They were put in by the armorer though and ordered through the supply system. It was more than just a single guy who brought his own bolt. The guys who had them didn't know the difference. I recognized them from the LW S2 marking on the lobster tail style extractor. I get that, but LWRCI said themselves that the issues with the ACB1 and ACB2 could not be fixed and that is why you cannot get them in 5.56. I would not want a bolt in my rifle that the manuf. Says is a faulty design and then abandons the design. |
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Posted: 3/30/2015 2:07:28 PM EDT
[#47]
Quote HistoryQuoted:
I don't have any background on when they were acquired. I was issued an M4, but several of the operators I was with had MK18 uppers and the bolts had been replaced with the ACB's. I am not aware how many the armory still had available or what the rules were regarding replacement. They were put in by the armorer though and ordered through the supply system. It was more than just a single guy who brought his own bolt. The guys who had them didn't know the difference. I recognized them from the LW S2 marking on the lobster tail style extractor. Quote HistoryQuoted:
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Thats the one. http://www.ar15.com/forums/t_3_118/641240_Official_Mk_18_and_CQBR_Photo_and_Discussion_Thread.html&page=472 According to CD it now has a 10,000 round replacement cycle. I am also curious how you got a LWRC ACB? They stated back when the M6IC was struggling to launch that they would come with standard bolts due to troubles producing the ACB. They to this day have no released any more ACB's in 5.56, just 6.8. I don't have any background on when they were acquired. I was issued an M4, but several of the operators I was with had MK18 uppers and the bolts had been replaced with the ACB's. I am not aware how many the armory still had available or what the rules were regarding replacement. They were put in by the armorer though and ordered through the supply system. It was more than just a single guy who brought his own bolt. The guys who had them didn't know the difference. I recognized them from the LW S2 marking on the lobster tail style extractor. Wonder why they went with those over LMT's enhanced bolt? |
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Posted: 3/30/2015 2:09:47 PM EDT
[#48]
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Wonder why they went with those over LMT's enhanced bolt? Quote HistoryQuoted:
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Thats the one. http://www.ar15.com/forums/t_3_118/641240_Official_Mk_18_and_CQBR_Photo_and_Discussion_Thread.html&page=472 According to CD it now has a 10,000 round replacement cycle. I am also curious how you got a LWRC ACB? They stated back when the M6IC was struggling to launch that they would come with standard bolts due to troubles producing the ACB. They to this day have no released any more ACB's in 5.56, just 6.8. I don't have any background on when they were acquired. I was issued an M4, but several of the operators I was with had MK18 uppers and the bolts had been replaced with the ACB's. I am not aware how many the armory still had available or what the rules were regarding replacement. They were put in by the armorer though and ordered through the supply system. It was more than just a single guy who brought his own bolt. The guys who had them didn't know the difference. I recognized them from the LW S2 marking on the lobster tail style extractor. Wonder why they went with those over LMT's enhanced bolt? No idea, but it is looking like a poor choice. |
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Posted: 3/30/2015 2:15:03 PM EDT
[#49]
Quote HistoryQuoted: Wonder why they went with those over LMT's enhanced bolt? Quote HistoryQuoted: Quoted: Quoted: Thats the one. http://www.ar15.com/forums/t_3_118/641240_Official_Mk_18_and_CQBR_Photo_and_Discussion_Thread.html&page=472 According to CD it now has a 10,000 round replacement cycle. I am also curious how you got a LWRC ACB? They stated back when the M6IC was struggling to launch that they would come with standard bolts due to troubles producing the ACB. They to this day have no released any more ACB's in 5.56, just 6.8. I don't have any background on when they were acquired. I was issued an M4, but several of the operators I was with had MK18 uppers and the bolts had been replaced with the ACB's. I am not aware how many the armory still had available or what the rules were regarding replacement. They were put in by the armorer though and ordered through the supply system. It was more than just a single guy who brought his own bolt. The guys who had them didn't know the difference. I recognized them from the LW S2 marking on the lobster tail style extractor. Wonder why they went with those over LMT's enhanced bolt? At some point you have to start replacing barrels anyways as with a heavy firing schedule they will be worn out fairly quickly. I normally keep a spare bolt around and I'll replace one if I break one. I have thought about getting an E-bolt for my bump gun as it routinely sees 750-1000rpm and chews through ammunition pretty quick. I think an E-bolt could outlast 5-10 barrels on it, lol. |
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Posted: 3/30/2015 2:16:02 PM EDT
[#50]
Quote HistoryQuoted: No idea, but it is looking like a poor choice. Quote HistoryQuoted: Quoted: Quoted: Quoted: Thats the one. http://www.ar15.com/forums/t_3_118/641240_Official_Mk_18_and_CQBR_Photo_and_Discussion_Thread.html&page=472 According to CD it now has a 10,000 round replacement cycle. I am also curious how you got a LWRC ACB? They stated back when the M6IC was struggling to launch that they would come with standard bolts due to troubles producing the ACB. They to this day have no released any more ACB's in 5.56, just 6.8. I don't have any background on when they were acquired. I was issued an M4, but several of the operators I was with had MK18 uppers and the bolts had been replaced with the ACB's. I am not aware how many the armory still had available or what the rules were regarding replacement. They were put in by the armorer though and ordered through the supply system. It was more than just a single guy who brought his own bolt. The guys who had them didn't know the difference. I recognized them from the LW S2 marking on the lobster tail style extractor. Wonder why they went with those over LMT's enhanced bolt? No idea, but it is looking like a poor choice. |
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