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6.8SPC FAQ (Page 2 of 3)
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OK, when I go to the DPMS web site and click on the complete rifles, they list the complete rifle with a 20" barrel as being a 1x10 twist. Click on the the "barreled assemblies" and the 20" uppers are 1x11 twist. Go click on the barrels and the 16" is listed as 1x10 twist, but the 20" barrel has no twist listed. 
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Myakka City, Florida.
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Hey Tim, You can add the following to the suppressors area: AAC made some M4 2000 6.8 cans last year, and I believe is still offering them as a custom item. Surefire also now offers dedicated 6.8mm bored cans, both those which mount back over the barrel, and those which mount to their flash suppressors as a fast-attach/detach style. I'll continue to update via reply here as more comes in, unless you prefer that I PM the info instead? |
"Texas - the only state that ever kicked another country's ass."
"I'll never forget September 11, 2001, those who have fought and died, or those who continue to fight to avenge the deaths of over 3000 innocent Americans"
"I'll never forget September 11, 2001, those who have fought and died, or those who continue to fight to avenge the deaths of over 3000 innocent Americans"
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Well, I'm just about done testing for the 20" barrel and this is what I have come up with: 1. For the 90-130 Gr. bullets it is hard to beat H322 for velocity and accuracy. It is the fastest powder with all of the bullets except the 90 Gr. bullets which gets edged out by H4198, but it is more accurate. And the powder is small enough that it meters perfectly through the Dillon press. It is also supposed to be temperature insensitive so it should maintain the same velocity at any temperature. 2. The best value in powders is Ramshot X-Terminator and the Accurate AA2230. I'll give the edge to X-Terminator in velocity and price (accuracy is about the same.). They are both surprisingly accurate and much cheaper than the other powders. 3. The Speer 90 Gr. TNT bullets are some of the most accurate and the best value bullets available. I buy the 650 round value pack. 4. IMHO, the two best All-purpose bullets are the SSA 115 Gr. SMK and the Sierra 110 Gr. Pro-Hunters. |
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| Added Barnes Tipped TSX to the chart. Also I talked with the tech dept at DMPS and they said all there barrels for the 6.8 are and have been 10:1 Sammi. I told them about the move by Shaw and they said that ery well may change there chambering as well. |
TW
[Two ears, one mouth. We were intended to use them in that order & ratio for a reason!]
[Two ears, one mouth. We were intended to use them in that order & ratio for a reason!]
The link to it has now been added after the "barrels" section and then again in the "other resources" section TW |
TW
[Two ears, one mouth. We were intended to use them in that order & ratio for a reason!]
[Two ears, one mouth. We were intended to use them in that order & ratio for a reason!]
When I recently called up and asked, the guy told me he "thinks" it is the improved chamber because they had talked about it and supposedly had changed it. If I were you, I would call and get a straight answer from them. If not, you can always buy some combat rounds and check for pressure signs. |
Visit www.68forums.com for all the info on the Remington 6.8SPC.
SAAMI-spec chamber and 1:9.5 twist mean the chamber is too tight and the twist rate too fast for SSA combat loads or the hotter handloads. In fact, 1:9.5 is just too fast for the 90-120 grain bullets available for 6.8SPC that load to mag length. On hot days, you may even see pressure signs with standard commercial ammo from Hornady and Remington. Model 1 may eventually see the light and go to the improved SAAMi chamber 1:11 barrels Shaw is now making available. |
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Not only that, you can't even get to the listed top loads in the manuals without pressure issues. They do have one use as Constructor has found. You can use the barrel for subsonic loads where you need extra pressure to make the action cycle properly. TW |
TW
[Two ears, one mouth. We were intended to use them in that order & ratio for a reason!]
[Two ears, one mouth. We were intended to use them in that order & ratio for a reason!]
mamasboy, Sometime people find it confusing when I tell them that my barrels with improved chambers and 1:11" twist four-groove rifling are made by Shaw. The fact is that my barrels are unique. Even though Shaw also makes barrels for Model 1 and Stag (among others,), my barrels have almost nothing in common with Shaw's other barrels. They have changed their 6.8 reamers to add the same 0.10" of freebore that we call the improved chamber, so that as other companies sell-off their old barrels, you will see the same chambers in their products. I had to buy the first rifling button to produce four-groove 1:11" twist rifling, and it took three tries before they got it right. The guys at Shaw call my rifling pattern "proprietary". A barrel maker works from a blank, and is dependent on the customer to tell them exactly what they want them to build. If the customer doesn't know exactly what they want, the maker will take the easy route and make something that they have sold to everyone else and requires little or no change to their process or tooling. In my first "generation one" barrels, we specified the chamber but not the rifling, and I got 1:9.5" six-groove rifling which offered only modest pressure and velocity improvement over other barrels. I had to tell them exactly how I wanted the rifling done, in order to get the rifling that worked. Shaw didn't design it, I did. The moral of the story is: barrel makers will make a barrel any configuration that the buyer wants. Just because three companies sell barrels that are made by the same barrel maker, you will very likely have three quite different barrels. In my case, Ko-tonics barrels are unique, and no other customer of Shaw gets barrels that are similar to mine. Hope this helps. |
<center id=center>Put your AR-15 on steroids: 6.8mm SPC</center id=center>
You know I don't completely buy into the twist being too fast hype on the Model 1 barrels. Many Model 1 barrels have shot just fine including the one I have had for 3 yrs. Will it do what the latest Ko-Tonics barrels will in terms of velocity or pressure? No, but neither will a great many other barrels. Saying the 9.5 twist is no good is like saying the 7" .223/5.56 twist is no good. My second 6.8 has a 10" twist barrel which I specifically ordered that way from WOA. Until the latest chamber/twist improvements I have not wanted an 11" twist barrel and honestly I am still a bit skeptical. Yes more velocity is there but the technique is not new or w/o problems. It remains to be seen whether it will be a problem at 6.8 velocities. Cartridges that this technique has been used in previously were somewhat higher velocity. |
The original SPC(Murray and Lawtons test rifles) did have a longer throat and could be loaded to higher pressures/velocities. When Remington got involved someone at Remington changed the dimensions on the reamer drawing before it was submitted to SAAMI. That along with Remington using a powder that was heat sensitive caused pressure problems so the loads were reduced to what we have now available on store shelves. They are not exactly high performance rounds. Your Model 1 9.5" twist should work just fine for factory ammo and mild hand loads but, I wouldn't try shooting my load of 29gr of RE7 behind 90gr TNTs that read 2900fps from an 18" barrel. |
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My barrel gives the same relative velocity levels of all the other 20" barrrels manufactured to the same SAAMII chamber and bore groove spec.. I.E. 2600-2650 with the various 110 gr. Hornady and Sierra bullets. That is in the same velocity range as all the other similarly manufactured barrels. The current Ko-Tonics barrel is a hybrid (for lack of a better term) at this point. It has a combination of chamber and land/groove that allows lower chamber pressure and an increase in velocity due to the reduced friction from the 4 groove/narrow land combination. This is not an entirely new concept. Similar things have been done in the past. Barnes even does it with one of their bullet lines. The freebore on my barrel is something like .070" with 110 gr. Hornady V-Max's seated to 2.305". It has more than my WOA barrel. I personally have no need for anything lighter than 110 gr. bullets. I think that 115 gr. is ideal and wish someone would come out with 120 gr. bullets at a reasonable price. That weight would be ideal for deer hunters and probably pig hunters too. Will it handle the hot "combat loads" probably not. But then a lot of other barrels won't either. I remember all the problems in the original 6.8 threads when SSA came out with them. I was one of the early posters of thread #1 so I remember a lot of problems along the way of working the kinks out of the round. Don't get me wrong. Developments can be a good thing just don't go around knocking what was done before. I would like to see what a 9.5"/10" twist would do with the same chamber and bore/groove as the current Ko-Tonics barrel has now. The twist itself has less to do with it than would think. Some loss yes but not as much as you may think. Look at the .223/5.56 twist rates. |
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It isn't the same as saying a 223 7:1 isn't ideal. Its like saying a 223 6:1 isn't ideal and it isn't, is it? I didn't come up with these facts. They come from controlled testing done by experts that know what they are doing, also from feed back from the many users out there now. The faster you try to spin a bullet, the more friction it creates. This is seen as pressure. The shorter a throat you have on a chamber, the shorter the bullet has to be seated, even if there's room in the mag. The problem early on with SSA, had to do with the fact the plated bullet design was causing it to swell before entering the leade and got shaved. That's why the bullet was eventually dropped. The other problem was caused by SAAMI, actually Remington, because the specs allowed for a ammo manufacturer to produce ammo in spec and a barrel company to produce a in spec chamber, but you won't be able to close the bolt on the round. If you could it could be so jammed into the lands that it would cause a severe pressure spike. The other problem was a batch of improperly out of spec chrome lined barrels. Kotonics chamber isn't exactly a hybrid. It's almost exactly the same as the one used in the original and current testing. It is also becoming the most popular choice of chambering, as is seen by the fact many manufacturers are switching to it. Shaw already has and they will not be producing any more SAAMI chambered barrels in 6.8. They supply, by far, the most barrels used in the AR and rifles in general, so this is pivotal. What does that tell you? They also won't be producing anymore 9.5:1 twist 6.8 barrels. What does that tell you further? The facts are this, having a excessively faster twist than needed, to stabilize the largest bullets for the cartridge, is not a positive and causes higher pressure. Will it work to a certain degree? YES. Is it "recommended"? NO. The largest problem with the Model 1 barrels is they have two things combined which cause a synergenic negative overall effect. They have a SAAMI chamber, they also have a very fast twist. Faster that any other barrel made out there for the 6.8, period. When combined, both of those features create a situation that is counter productive to top performance, because of excessively high pressure. A 10:1 will stabilize bullets over 150 gr and those are way to heavy for the 6.8. So, going to a 9.5:1, which is even considered a fast twist for the 270 Winchester, its standard twist is 10:1, which uses much heavier bullet that the 6.8, is ill advised. I guarantee you when Model 1 finishes selling those inventories off of 9.5:1 barrels you won't see them selling them anymore. The fact that an 11:1 twist rate will stabilize bullets up to and over130 + grains should be a good indicator of what's needed. Again, no where in the Chart or here in this thread, did any one say, "you can't shoot a 9.5:1 barrel in a 6.8SPC configuration", its just not recommended; right along with not getting 8 hours of sleep every night. If you have one, shoot it, just watch for pressure signs if you hand load and try to approach the upper ends in the manuals. If you want to shoot faster loads, sell it and get something from the chart that fits what you want performance wise. The chart is there to inform people of the facts, not my or anyones personal opinions. The fact is you will never get near the full performance potential out of the 6.8 SPC cartridge with a 9.5:1 twist, SAAMI chambered barrel. You won't even get close. Its been proven consistently over and over again. Now, as to the twist not making that much of a difference and that it's more the chamber and specially design and number of grooves. That has been proven clearly incorrect. WOA barrels are 11:1 twist, 6 groove , SAAMI chambered, configurations from WOA and Denny's. Many have these barrels. They can shoot rounds as hot as you can get, until you run out of room for powder, in many instances. They easily handle the combat loads from SSA. Note: not the extreme bullets as they needed the extra throat length to handle the deformation of the tail of the bullet. The real benefit of the extended throat is allowing proper seating of the bullets in ratio to the magazine dimensions. To close or into the lands causes pressure spikes in a gas gun. It further more allows for those variances in ammo OAL. They also allowed the use of the extreme bullet, as this was the chosen and requested training round for the military. Can you say cheap. Actually, they stumbled onto it in reverse, but those are the effects, regardless. The twist absolutely makes up a major part of the difference, if not the defining difference. Let let me explain this further. Take a SAAMI chamber with a 10:1 twist and you get pressure signs with Combat or high velocity loads. Change the twist to 11:1 and it can handle them without issue. What's happening to allow them to work in the 10:1 Improved SAAMI chambers is because there is still a long leade to the lands for the bullet because of bullet seating depth. It allows the gases to have more room to expand before the bullet engaging the lands creates friction and increases pressure. If you were to seat those bullets out to just off the lands like they would be in a SAAMI cut chamber, you would have the exact same pressure problem, regardless of the throat length in a 10:1 or faster twist barrel. But now slow the twist to 11:1 or slower, 12:1 twist rates will work up to about 120 gr bullets, and the pressure problems go away irregardless of which throat length you choose. As long as you aren't jamming the bullets into the lands which would cause a pressure spike in any barrel in any chambering or twist rate. The only thing different between the SAAMI and Improved SAAMI is the increased throat length. Check out the drawing link. Nothing else is changed. So if you eliminate that, by setting the bullet long, it is completely negated. But change the twist and irregardless of the throat specs the pressure drops compared to 10:1 or faster. The ammo dimensions have no effect on this feature. Now, the number of groove hasn't been throughly test in a controlled environment yet. So to say what or how much of an effect it has would be premature. My bet is less effect than the others but still some benefit. So, to recap. The extended throat works by giving more room for the expanding gases and increase velocity by giving the bullet a running start up before engaging the lands/rifling. It also allows maximum seat length with the magizine dimensions now being the limiting factor. The slower twist rates work by causing a decrease in friction. By not causing the bullet to have to twist at a more sever angle of the faster twist rate pressure is reduced while then being able to increase the charge allows for higher velocities to be realized. The reduced number of grooves are suppose to work by the theory that, with less surface engaging the bullets ogive surface the less friction is created. Its similar to why they use gas rings on some bullets so that there is still a pressure seal but the part of the bullet touching the rifling is taken to a minimum. This is shown in how much faster you can send a 110 Barnes TSX versus a 110 Sierra Pro hunter. The different designed rifling are suppose to create a better seal between the bore and bullet. They are also suppose to reduce friction by reductions in contact area and reduce bore fouling. Now what Kotonics has done, is to put it all together. The 11:1 twist rate is enough twist to stabilize the heaviest bullets the 6.8 can realistically use; past the 130's. Combined with the extended throat which allows you much more liberty to bullet seating length and further allowed the use of the extreme bullet without causing pressure issues. It also corrected the overlap problem with the SAAMI specs. Finally the 4 groove which there is evidence that it reduces friction and fouling along with easier cleaning with indications of lower pressure. They also had the lands made shallower than typical which in theory should create less friction and help fouling as well. They finally added proper chrome lining for durability. Combining those things all together in one barrel creates an excellent environment for the 6.8 SPC to show its maximum potential in a AR-15 format. If you look at the chart of the different barrel configurations and what they can handle, you can see how the different setups effect what can and can't be used. What it comes down to is, if you want to load to the high end you need one of the improvements, either a 11:1 or slower twist or the longer throat or any combination of the two. With the Improved throat it is almost impossible to seat bullets to the lands and still have rounds at mag length so you will always have some extra leade. Hence, why it works consistently to lower pressure. The same thing Weatherby did to use its high velocity rounds. Note that all Weatherby produced ammo comes with posted warnings to "only use in Weatherby produced rifles". You are right in the fact that none of this stuff is new to the firearms industry as a whole. What is new, is its combining of these things in one package for use with are cartridge built to take advantage of them specifically in the limitation of a gas gun like the Ar-15. Many of these features wouldn't matter as much in a bolt gun as it has much more chamber support and you can load bullets as long as you wish by extending the leade. The bolt itself is also many times more durable than the inferior, strength wise, AR designed bolt. In the end, facts are still the facts. The Model 1, Shaw produced, 9.5:1 twist rate, SAAMI chambered barrels are not recommended for 6.8 SPC AR-15 rifles because all the facts and testing arrive at that conclusion. Not because of your, mine or anyones personal opinion. Using a 9.5:1 twist rate, SAAMI chambered barrel handicaps the performance of the 6.8 SPC round in an AR15 format and can and will cause unsafe pressure spikes if the true performance potential of the 6.8 SPC is attempted. This can and will cause damage to rifle and human alike if pushed. Furthermore its because of the existence of these type of barrel configurations, and the fact that ammo manufactures must load to the lowest common denominator for safety concerns, that you see the lower velocities from the production ammo you have today, compared to what has been tested and proven to safely work in differently configured barrels. For example I can safely get 2950 FPS from 90's Sierras, 2800+ from 110s Barnes, 2700 from 115s Sierras, 2650 from 120s Barnes, and finally 2500+ from 130's Speers. All of this from a SAAMI chambered 11:1 16" WOA barrel. Constructor can handily surpass those with his 18" WOA SAAMI 11:1 barrel You can't even begin to approach these velocities with a 9.5:1 twist rate 20" barrel. Give me the powder resources of a ammo company and I bet I could add at least 50-100 FPS to that. Now add in extending the throat some to allow for better seating to maximize the magazine loaded length size and 5R or other non standard rifling and you lower the pressure some more which decreases wear on parts and an increase in accuracy to boot. The limiting factor then becomes the case size dimensions as apposed to the rifle barrels configurations. You can only stuff so much powder in that little case. That's when you know you have or are reaching the maximum potential of a particular cartridge, instead of the maximum potential of a certain parts design of a rifle configuration. Take those velocities with some of new bullets that are coming out with .400 and better G1 BCs and it starts to become very exciting all over again. TW |
TW
[Two ears, one mouth. We were intended to use them in that order & ratio for a reason!]
[Two ears, one mouth. We were intended to use them in that order & ratio for a reason!]
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Originally Posted By Tim_W: ....... And there you have it, folks. I'm glad Tim W has entered the game with us. For three years, this question has been in the making, and, many of us, (though I am certainly not one of the true experts) believe that answer finally consolidates all the facts as they are currently known. Bravo, sir, a truly great post.  There are quite a few people on this board, who would surely agree with this 100%, because the truth is the truth. Now, I hope that we can all move forward from this moment on, and watch as the 1:9.5" twist barrels, and the original SAAMI chamber just slowly go away, forever. Most Mfr's seem to have this figured out as the SAAMI chamber seems to be less and less popular these days, thankfully. ER Shaw ceasing production of the SAAMI chamber (in favor of the improved) speaks volumes. ** BTW, I own one of the Model 1 barrels. I liked the upper FWIW, but have "graduated" to the KO-Tonics, and it is more accurate, and allows me to shoot hotter loads. Why is this so important to me? Because I happen to like the Barnes X and the new tipped TSX bullets. When shooting huge hogs, velocity does matter, and if I am going to push this load FAST, I need the gun to handle charges which can push this thing into the 2650-2700 FPS range, to get the expansion I want. I just didn't feel safe pushing things with my Model 1 barrel, because I saw pressure signs with lesser loads. YMMV |
"Texas - the only state that ever kicked another country's ass."
"I'll never forget September 11, 2001, those who have fought and died, or those who continue to fight to avenge the deaths of over 3000 innocent Americans"
"I'll never forget September 11, 2001, those who have fought and died, or those who continue to fight to avenge the deaths of over 3000 innocent Americans"
No River-rat, it certainly wasn't solely directed toward you. Your questions and statements, to be honest, did initiate my response. It was more you brought up some areas where I could see things were unclear and not fully explained. These could have caused others to raise all the different things I addressed in there. It also comes down to, I tend to ramble on and on. I just hate not to be as clear as possible in what I say on the internet. We all know how people can and do misinterpret and read into what they want, so, I was just trying to be a clear and through as I could be. It was in no way meant to put words in your mouth or to inject different meanings into what you had written. Only a few points were direct towards you and only to further answer those same questions for others that might be in similar situations. I have very thick skin and very rarely take or make something personal. My main rule how I conduct myself over the internet and in general is I only speak to people as I would if I were having that same conversation in person in civilized surroundings. It seems to prevent much of the petty personal attacks and bickering. Now, See how I ramble on.  Thanks for not taking offense and asking.Tim
I agree with River_Rat The problem discussed here were one early on in the 6.8's release. If you have a bullet comparator and a calipers you can measure your loaded round and see if it is inside the correct specs. To really get it done proper get the Hornady OAL Gauge that gives you the measurement of the actual length of the chamber with each particular bullet to the lands. You should definitely try to get a good set of calipers and comparator when you can afford. The OAL gauge will also save you a lot of trail and error in making your ammo. If we want to continue with this problem can we start an new thread as to keep this one on track. Thanks and no offense meant.  Tim |
TW
[Two ears, one mouth. We were intended to use them in that order & ratio for a reason!]
[Two ears, one mouth. We were intended to use them in that order & ratio for a reason!]
Nope The same mesurment as the Hornady 110 v max. But the bullets do not have the Canture <(spelling?) could that be the problem? 
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Tim No offense taken and most of what you say I do agree with and some I partly agree with. To each their own. I too would like to see some powders developed for the 6.8. I have always thought that they are all just a bit too fast or a bit too slow or just a bit too bulky. It seems to me that the loading density, especially now with the new barrel configuration, is getting pretty high. Mamasboy I tried to IM you but your IM is turned off. Turn on your IM and IM me and I'll see if I can help. |
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River_rat, I think over all everyone finds H322 to be the most consistant SD and the most accurate. It seem to have the right combinations for all 6.8 bullets. Its also fairly clean The only problem is you can't get enough of it in the case to maximize velocity. IIRC if you compress it to much you actually get a velocity drop. So a higher density H322 equivalent is what I would think would be the ideal powder. The fastest velcities across the board can be found most of the time with H355. In to 90's 4198 is ideal. Rel 7 work well to. I think it would really shine in short SBR under 12" If you take the velocity Remington got with there powder. Forget about it being temp sensitive. It would get us numbers close to these in a 16" barrel: 130/2650, 120/2700, 115/2800, 110/2925, 100/3000, 90/3100. Now wouldn't those numbers be great. Screw temp sensitivity I'll keep my ammo out of the sun if I can have that type of performance. Also remember when they got the 2800 with the 115 bullet they were using long throat chamber 10:1 standard riling barrel. Combine that long throat 11:1 twist 4 shallow groove specs and the the icing on the cake the LWRC superbolt. Pressure shouldn't be an issue. Accuracy would be good. Chrome lining would give durability. Add a heavier buffer system to handle the thrust and OOHHH baby you have one hell of an effective combat round. Now add a 105-120 .450 BC bullet and you are effective past 1K, out of a 16" barrel none the less. What is great is these things I believe are possible. The round is still so new in the commercial venue. It still has some growing to do. Look how far the .223 and .308 have come in powders and bullet development. We have the benefit of current technology compared to them so thing happen much much faster. I'm glad you like your rifle and I take my hat off to you as you were in this game of 6.8 use long before me. I'm also glad we can agree on some points and the disagreement on others is the way progress works. I find it a positive as long as its handled the way we are here with mutual respect. I agree with you on I would also like to see more 120s as well. I think its the sweet spot for hunters that find the performance drop of going to the 130s to much but don't find the lighter 115's effect enough for there personal liking for whatever reason. I do think this year is going to have movement with this rounds maturity. SSA is ready to release their new low cost plinking round right as ammo price are about to take another jump. This will put it into the same price range as 223 ammo. We are already there if you look at premium loadings. We now have 3-4 bonded offerings and 2 AP rounds thing are look good. Tim |
TW
[Two ears, one mouth. We were intended to use them in that order & ratio for a reason!]
[Two ears, one mouth. We were intended to use them in that order & ratio for a reason!]
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When I started with the 6.8 the only readily available data was Zak's. This was back in Sept. '04. I have played with several powders. Have mostly settled on RL-10X and H322. I have tried others with a couple I may try again sometime with 115 and heavier bullets just to see what happens. I definitely agree that the 6.8 has a fair amount of room for development. It is a very interesting round with untapped potential. |
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I have added a write up by screen name: paulosantos. Thank you Paul for all your hard work. Hope it was OK to add this. Here is what was added just before the loading recipes: Choosing the Proper .277 Bullet for Use in the 6.8SPC Writen By User Screen Name: PaulOSantos INTRO: I have put together this thread as an informative thread for the new guys or anyone else who needs help with selecting the correct .277” bullets for reloading for the Remington 6.8SPC. Before I begin, I just want to touch up on the Remington 6.8SPC. If you are using the 6.8SPC in an AR-15, there is an OAL that you have to keep in mind. With the C-Products and Barrett magazines, I would not load the ammo longer than 2.260" to load reliably. If you have PRI magazines, I would not load the ammo longer than 2.280". Also, due to the limited powder capacity, it is best to load bullets in the range of 90-115 Gr., although you can load some of the 130 Gr., you will be hard pressed to get velocity over 2200fps. POWDERS: So far, I have tested a boat load of powders and the best powders are definitely the medium-fast powders such as H322. As far as velocity, I've found that for the 90-100 Gr. bullets, the H4198 is hard to beat and it is very accurate. H4198 is ok for the 110 Gr. bullets, but the velocity is not as good as the H322 and you will need a light buffer or else you may have cycling problems, especially with the rifle length buffer tubes. If given a choice, I would start with the Hodgdon Extreme Powders since they are very accurate and they are not as sensitive to temperature changes as some of the other powders. Also, I would prefer a extruded powder over ball powder since they are generally more accurate. Best Powders for 90-100 Gr. Bullets: 1. H4198. 2. H322. 3. H335. 4. X-Terminator. 5. Reloaders 7. Best Powders for 110-135 Gr. Bullets: 1. H322. 2. Benchmark. 3. Reloaders 10x. 4. 2015. 5. H335. 6. N133. 7. X-Terminator. 8. TAC. 9. 2230. RIFLE TWISTS: The two most popular twists for the Remington 6.8 SPC are the 1:11" twist and the 1:10" twist. Both twists can handle bullets from 90-135 Gr., but the 1:11" twist is supposed to reduce the pressure and is quickly becoming the popular choice. BULLET TYPES: 1. FMJ-Full Metal Jacket (Ball Ammo). Unknown at what velocity the Remington FMJ fragments, but the SSA Extreme FMJ is supposed to fragments at 2100+ fps. 2. OTM-Open Tip Match. HP-Hollow Point. SMK-Sierra Match King. Generally fragments at 2100+ fps. 3. SP-Soft Point. Generally expands at 1700+ fps. 4. BT-Ballistic Tip. Generally expands or fragments at 1900+ fps. NOTE: You may see the letter "BT" (Boat-Tail) in front or after the above ammo types. BT stands for "Boat Tail" and refers to the base of the bullet. A "Boat Tail" is a sloping end which narrows gently at the base of the bullet, so that the cross-section resembles the shape of a boat's hull. The boat tail shape reduces drag on a bullet, helping it to retain velocity and resist deflection from crosswinds, but causes the bullet to take longer to "settle" after leaving the barrel compared to a standard "flat-base" bullet. Boat tail bullets are usually selected for long-range shooting, while the flat-base bullet shape tends to be more accurate at short ranges. A "HPBT" bullet is a "Hollow Point Boat Tail" bullet. The last thing I would like to explain is a “Cannelure.” A Cannelure is a cut or pressed groove (or grooves) around the shank of a bullet. Cannelures provide an area into which the case mouth may be securely crimped. Military ammo has cannelures to prevent bullet set-back. Bullets with cannelures are not generally used in match ammo because cannelures may decrease the accuracy of the bullet. For Military/LE purposes, bullets with cannelures are preferred. For sniper type applications, bullets without cannelures are usually used. HOME PROTECTION/SHTF: Penetration and Fragmentation are key for Home Protection/LE applications. 10-12" is ideal to ensure that it will reach the vital organs. 1. Hornady: a. 100 Gr. SP. b. 110 Gr. V-Max. c. 110 Gr. HP. 2. Remington: a. 100 Gr. SP. b. 115 Gr. FMJ. 3. Sierra: a. 110 Gr. SPT. b. 115 Gr. SMK. 4. Silver State Armory: a. 115 Gr. SMK Enhanced Fragmentation Version. BARRIER PENETRATION BULLETS: 1. Barnes: a. 110 Gr. Barnes XXX. b. 110 Gr. Barnes tipped XXX. 2. Nosler: a. Accubond 110 Gr. Spitzer. b. Accubond 130 Gr. Spitzer. c. Ballistic Tip 130 Gr. Spitzer. 3. Remington: a. 115 Gr. Core Lockt SP. 4. Sierra: a. 110 Gr. SPT. b. 130 Gr. SPT. c. 130 Gr. SBT. 5. Speer: a. 130 Gr. SP. b. 130 Gr. BTSP. HUNTING BULLETS: For hunting bullets that expand/mushroom are preferred because they don’t damage too much meat like the fragmenting bullets. 1. Barnes: a. 110 Gr. Barnes XXX. b. 110 Gr. Barnes tipped XXX. 2. Hornady: a. 100 Gr. SP. b. 110 Gr. HP. c. 130 Gr. Interbond. d. 130 Gr. SST. e. 130 Gr. SP. 3. Nosler: a. Accubond 110 Gr. Spitzer. b. Accubond 130 Gr. Spitzer. c. Ballistic Tip 130 Gr. Spitzer. 4. Remington: a. 100 Gr. SP. b. 115 Gr. Core Lockt SP. 5. Sierra: a. 90 Gr. HP. b. 110 Gr. SPT. c. 130 Gr. SPT. d. 130 Gr. SBT. 6. Speer: a. 100 Gr. SP. b. 100 Gr. HP. c. 130 Gr. SP. d. 130 Gr. BTSP. MATCH/COMPETITION/SNIPER BULLETS: 1. Hornady: a. 110 Gr. V-Max. b. 110 Gr. HP. 2. Sierra: a. 115 Gr. SMK. b. 135 Gr. SMK. 3. Speer: a. 90 Gr. TNT. Note: Cannelures are generally not used because of possible accuracy loss. VARMINT HUNTING: Varmint Hunters want a bullet that offers great accuracy and rapid expansion. Some of the best bullets for Varmint hunting are the lighter 90-100 Gr. Bullets. 1. Hornady: a. 110 Gr. V-Max. 2. Sierra: a. 90 Gr. HP. 3. Speer: a. 90 Gr. TNT. b. 100 Gr. HP. PLINKING BULLETS: 1. Remington: a. 100 Gr. SP. b. 115 Gr. FMJ. 2. Speer: a. 90 Gr. TNT Value Packs. Again Thank you Paul for all your hard work. Hope it was OK to add this. ETA: I added these lines under plinking bullets because I know SSA already has them made based on phone conversation with the receptionist. Just waiting for their release. Oh Art!?!  Silver State Armory: a. ? very soon 115 FMJ ? Tim Tim |
TW
[Two ears, one mouth. We were intended to use them in that order & ratio for a reason!]
[Two ears, one mouth. We were intended to use them in that order & ratio for a reason!]
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Damn, Kotonics is closed until January 2nd or 3rd. I called them with a couple questions...fully expecting to give them an order. Will the bolt fit a standard 5.56 carrier? Will they install the flash hider I buy before shipping the upper out? When do they expect to have in stock the Sierra 115 gr. OTM (MK w/ cannelure) Bullets and SSA brass? And do they have any of the 16" Combat Edition uppers in Stock? I can't wait. |
Guns? Guns? I don't have any guns. Now Uncle Fester down the road, he has some guns, and occasionally he lets me shoot them.
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Visit www.68forums.com for all the info on the Remington 6.8SPC.
www.ar15.com/forums/topic.html?b=3&f=118&t=351239 |
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Good news. RRA just confirmed that they use the Improved 6.8 chamber, and also use extended feed ramps. This is good news to the 6.8 industry, because there is now a 6.8 upper that sells for 500 dollars shipped, that uses the correct and improved chamber, and extended feed ramps. Here is the info, www.ar15.com/forums/topic.html?b=2&f=38&t=157977 |
My only question to RRA is this: Do they use M-4 Barrel Extensions in their 6.8 SPC uppers? Their .223/5.56 rifles and carbines use Rifle Extensions and all they do is break the edge of the upper, so as to better feed HP and SP ammo. To my mind semi-auto .223/5.56 AR's really do not NEED M-4 Barrel Extensions, but they SHOULD standard on a 6.X AR. |
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Hey Tim, could you fix those chamber names so someone that wants a 6.8 SPC II doen't end up with a SAAMI spec. because he called it the SAAMI II ? 6.8mmx43 REM.=SAAMI 6.8mm Rem SPC II= improved Those are listed on the prints, if you call them the wrong things you may not get what you want. |
6mmBanshee and 5.56x42 two of the flattest
shooting calibers for the AR15
does everyone ignore your post? are you a jackass?
www.AR15Performance.com
www.68forums.com
www.SSArmory.com
www.ammoguide.com
shooting calibers for the AR15
does everyone ignore your post? are you a jackass?
www.AR15Performance.com
www.68forums.com
www.SSArmory.com
www.ammoguide.com
constructor what do you think a douglas s.s. 1-11 twist air guge barrel will do with higher pressures. chambered with a SAAMI spec. Reamer . Want to load around 110 V-max 29.0 gr. of H -322 think I can do that working up slowly I have been loading for 35 yrs. and shoot a lot of bench rest. FRANK white at COMPASS LAKE ENG. is chambering it now and I can not cancel out on him. not a nice thing for me to do to him after I already made a deal with him..
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I will just edit those then. I'm about half way through revamping the whole thing with spread sheets etc.. I'll email you what I have after I finish the section I'm on to get some more ideas. Tim |
TW
[Two ears, one mouth. We were intended to use them in that order & ratio for a reason!]
[Two ears, one mouth. We were intended to use them in that order & ratio for a reason!]
|
OK I did some quick fixes. I changed the names to reflect the SPC II instead of SAAMI Improved or any other usages to mean the same. I fixed the RRA offering to reflect the SPC II change I deleted the loading info and add the JPEG image version with the completed data. Again this isn't the final updated version I am working on just a patch job to correct info and update the load recipes to a reflect all I could find and an easier format. This reformat is taking longer then I thought, as there is new info and changes. Then getting it all in a format that makes finding and referencing easy. But it's getting there. Tim |
TW
[Two ears, one mouth. We were intended to use them in that order & ratio for a reason!]
[Two ears, one mouth. We were intended to use them in that order & ratio for a reason!]
|
SPC II Reamer drawing SAAMI Drawing |
6mmBanshee and 5.56x42 two of the flattest
shooting calibers for the AR15
does everyone ignore your post? are you a jackass?
www.AR15Performance.com
www.68forums.com
www.SSArmory.com
www.ammoguide.com
shooting calibers for the AR15
does everyone ignore your post? are you a jackass?
www.AR15Performance.com
www.68forums.com
www.SSArmory.com
www.ammoguide.com
|
Any word yet on the Nosler 110 Accubond? Discussions of it seem to have died. I received my Midway bible yesterday and it's not listed in there????????? Anyone? |
Guns? Guns? I don't have any guns. Now Uncle Fester down the road, he has some guns, and occasionally he lets me shoot them.
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They show coming soon on Midways site. They were originally suppose to be out in January. Then again when has anything ever be out when it was scheduled to in this industry!?! Tim |
TW
[Two ears, one mouth. We were intended to use them in that order & ratio for a reason!]
[Two ears, one mouth. We were intended to use them in that order & ratio for a reason!]
| Will a standard flash hider work for the 6.8, or does it need to be one specifically for 6.8? I'm thinking of the Phantom 5C2 for my next upper, but I don't know if I can buy just any FH, or if it has to be 6.8-specific. |
Tempus fugit. Frater, memento mori.
"There are not over a hundred people in the United States who hate the Catholic Church. There are millions, however, who hate what they wrongly believe to be the Catholic Church" ~Bishop Fulton Sheen
"There are not over a hundred people in the United States who hate the Catholic Church. There are millions, however, who hate what they wrongly believe to be the Catholic Church" ~Bishop Fulton Sheen
6.8SPC FAQ (Page 2 of 3)
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