AR Sponsor
Posted: 11/23/2013 12:01:56 PM EDT
| The 'BCG vs. upper wear' thread got me wondering about piston pro/cons (I've been debating - in my head - between yet another DI gun or a piston for my next AR). A poster mentioned that piston action does not force the carrier straight back as in DI. I get that - makes sense, BUT, the question is about additional wear to the upper receiver - is there enough lateral force that additional friction is created? Did anybody here get a piston gun and find that it experienced additional receiver wear? Any other issues that came up due to the piston? Just looking for some real-life cons regarding piston guns - I have yet to hear any, but this might be a valid concern, although AKs sure seem to like them... |
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I had an Adams Arms piston system on a 16" Rainier build I did.
The only con that stopped me from getting another was cost and additional parts. The DI AR is a very simple setup with only a few moving parts. Adding the piston and op rod can, and have caused some extra failures. |
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although AKs sure seem to like them... A firearm designed for piston operation like an AK has provision to deal with the stresses and motions of the B/BC. Generally this takes the form of a B/BC riding on "rails". Piston operated actions also put the recoil spring in opposition to the piston or at some intermediate location so as to reduce the rotational forces. Generally the moving parts contact points are steel-on-steel to stand up to wear vs a steel-on-aluminum or similar situation. The AR15 platform has neither of those, as it was not designed for piston operation. The general approach has been to enlarge the contact areas between the BC and the receiver and receiver extension/buffer tube to try to limit the amount of wear. Also changing the parts fit a little to reduce the twisting forces put on the bolt. |
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If you don't get a kit or upper that has an anti-tilt BCG, you can have problems with the bolt carrier eating up your buffer tube. I believe that most of those problems have been solved now a days, though.
I've never owned or shot a piston AR. Just know about a few of the quirks and claims. I wouldn't listen to the "it runs at a much cooler temperature than DI" claim. Try to touch the gas block after firing a piston gun. You're just moving the heat from the upper to the gas block. Also, your run of the mill AR is not a DI gun. It's rather an internal piston design. The bolt is acting as the piston, (which is why the bolt has 3 compression rings around it) instead of having an op rod. My regular use AR has not had very many malfunctions (like 3 or 7) in the thousands I have put through it in the 6 years I've owned it. Getting a piston gun does add more weight and more moving parts, and it might afford you some more reliability. I guess I'm just part of the "if it ain't broke, don't try to fix it" crowd. Yours, and others mileage may vary... |
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I got sucked in by lure of the piston. I had an LWRC M6A2. It was accurate and reliable. While there were no problems, I did find that I preferred a DI gun for a few reasons.
-Less moving parts (it dawned on me how fallacious adding several new moving parts instead of a just gas tube was) -Better balanced (IMO anyway) -Parts availability (LWRC at the time would not sell me additional piston parts) -Even with anti tilt carrier I was vexed about visible buffer tube wear and gouges in the upper from the cam pin One thing I found interesting about the "shits where it eats" crowd is that the system vented gas under the rail. So no instead of "shitting" in the receiver where it was more or less contained it would "shit" all over my hand and blow back onto my optic. Anyway thats my experience, others may differ. |
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A firearm designed for piston operation like an AK has provision to deal with the stresses and motions of the B/BC. Generally this takes the form of a B/BC riding on "rails". Piston operated actions also put the recoil spring in opposition to the piston or at some intermediate location so as to reduce the rotational forces. Generally the moving parts contact points are steel-on-steel to stand up to wear vs a steel-on-aluminum or similar situation. The AR15 platform has neither of those, as it was not designed for piston operation. The general approach has been to enlarge the contact areas between the BC and the receiver and receiver extension/buffer tube to try to limit the amount of wear. Also changing the parts fit a little to reduce the twisting forces put on the bolt. Cast this in bronze and set it up under a library light. The AR platform was never designed to be piston driven. Moon |
My first post on AR15.com. 
I have owned two different Piston AR15's (LMT and PWS). Of course I live in CA, so I can't get to use sound suppressors etc. so I don't see the real benefit of a piston rifle except that the inside of the upper stays cleaner vs. a DI around the BCG. I now have two DI AR15's and I am currently building number 3. I found the Nib Bolt Carrier Group to be a nice option for a DI AR15. I do own AK rifles, and they are my favorite Piston Rifles... 
Thanks, socalakm |
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Piston is better for me:
more reliable (less dirty, less heat, less oiling) especially more reliable for SBRs no gas in the face when suppressed water in gas tube isn't an issue if that's a concern Down side is more parts, proprietary parts, slightly heavier...these really aren't an issue for me or most people slightly more recoil but that's why its better for SBRs ....and this can be overcome by a heavier buffer which I use in all my ARs with GT and GP anyway. accuracy doesn't change either doesn't matter if the AR was not originally designed for a piston...that's just foolish thinking. I wasn't designed to have many of the things it has now. The AR wasn't designed to be 1/7 twist, have rails, etc... The piston makes it a better weapon for the above reasons. |
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Piston is better for me: more reliable (less dirty, less heat, less oiling) especially more reliable for SBRs no gas in the face when suppressed water in gas tube isn't an issue if that's a concern doesn't matter if the AR was not originally designed for a piston...that's just foolish thinking. I wasn't designed to have many of the things it has now. The AR wasn't designed to be 1/7 twist, have rails, etc... The piston makes it a better weapon for the above reasons. That's a bold claim without any source or study. The piston has been proven to be a novelty on AR-15's. Some manufacturers make quality versions, but if you want a true piston gun, get an AK, SIG 556, or SCAR. |
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I agree with all that's been said above. I still choose Piston. Yes, it wasn't designed for it, but they've made it work. Evolution. The current offerings are adaptations for pistons, not a properly designed piston system. However, I still choose the piston for my overwhelming reason of "less maintenance". It still fouls, but it does so on a non critical point. Who cares if it dumps carbon ON a barrel? I'll take carbon ON the barrel any day over IN the receiver, BCG, bolt, and all the critical workings that make it go bang. I could care less how much it dumps under the hand guard. It's not harming anything there. I like to maintain my firearms WHEN I can, not because I NEED to.
I have nothing against DI. It's a pure, simple, and effective system. Less moving parts, lighter, and it works. But I detest a firearm that keeps ("the clock is ticking... clean me") in the back of my head the moment I squeeze off the first round. I don't get that with piston systems. To each their own. That's why the AR platform is so popular... so much to do (or not do) with it!
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That's a bold claim without any source or study. The piston has been proven to be a novelty on AR-15's. Some manufacturers make quality versions, but if you want a true piston gun, get an AK, SIG 556, or SCAR. Quoted:
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Piston is better for me: more reliable (less dirty, less heat, less oiling) especially more reliable for SBRs no gas in the face when suppressed water in gas tube isn't an issue if that's a concern doesn't matter if the AR was not originally designed for a piston...that's just foolish thinking. I wasn't designed to have many of the things it has now. The AR wasn't designed to be 1/7 twist, have rails, etc... The piston makes it a better weapon for the above reasons. That's a bold claim without any source or study. The piston has been proven to be a novelty on AR-15's. Some manufacturers make quality versions, but if you want a true piston gun, get an AK, SIG 556, or SCAR. just makes sense....less dirt, less need for oil, more force directed rearward with a solid rod than air = more reliable. why does a 7 inch SBR piston upper works better than a 7 inch gas tube upper? even if they are both equally reliable....the piston still has more advantage. for example less oil needed and less gas in your face and where has this been proven a novelty? where is your source or study? there may be I just didn't see one I base it on my use of my 8 ARs. 4 are pistons and others have gas tubes. And I would take my Sig or CMMG or POF over any of my other gas driven ARs. The idea that shooting 500 rounds through one with a gas tube requires oil and is filthy is just one of the reasons why |
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just makes sense....less dirt, less need for oil, more force directed rearward with a solid rod than air = more reliable. why does a 7 inch SBR piston upper works better than a 7 inch gas tube upper? even if they are both equally reliable....the piston still has more advantage. for example less oil needed and less gas in your face and where has this been proven a novelty? where is your source or study? there may be I just didn't see one I base it on my use of my 8 ARs. 4 are pistons and others have gas tubes. And I would take my Sig or CMMG or POF over any of my other gas driven ARs. The idea that shooting 500 rounds through one with a gas tube requires oil and is filthy is just one of the reasons why Quoted:
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Piston is better for me: more reliable (less dirty, less heat, less oiling) especially more reliable for SBRs no gas in the face when suppressed water in gas tube isn't an issue if that's a concern doesn't matter if the AR was not originally designed for a piston...that's just foolish thinking. I wasn't designed to have many of the things it has now. The AR wasn't designed to be 1/7 twist, have rails, etc... The piston makes it a better weapon for the above reasons. That's a bold claim without any source or study. The piston has been proven to be a novelty on AR-15's. Some manufacturers make quality versions, but if you want a true piston gun, get an AK, SIG 556, or SCAR. just makes sense....less dirt, less need for oil, more force directed rearward with a solid rod than air = more reliable. why does a 7 inch SBR piston upper works better than a 7 inch gas tube upper? even if they are both equally reliable....the piston still has more advantage. for example less oil needed and less gas in your face and where has this been proven a novelty? where is your source or study? there may be I just didn't see one I base it on my use of my 8 ARs. 4 are pistons and others have gas tubes. And I would take my Sig or CMMG or POF over any of my other gas driven ARs. The idea that shooting 500 rounds through one with a gas tube requires oil and is filthy is just one of the reasons why +1 anytime you have less crap coming back in you've made it more efficient and to argue otherwise is stupid. pros and cons to both systems so get what you want. I have both and enjoy both |
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I found it interesting that an AR is actually an internally driven piston system.
TECHNICAL NOTE 54: DIRECT IMPINGEMENT VERSUS PISTON DRIVE
"The AR-15/M16 and the AR-10 family of rifles employ a unique gas powered operating system patented by Eugene Stoner in the 1950s. This gas operating system works by passing high pressure propellant gasses tapped from the barrel down a tube and into the carrier group within the upper receiver, and is commonly but incorrectly referred to as a “direct impingement” system. The gas expands within a donut shaped gas cylinder within the carrier. Because the bolt is prevented from moving forward by the barrel, the carrier is driven to the rear by the expanding gasses and thus converts the energy of the gas to movement of the rifle’s parts. The bolt bears a piston head and the cavity in the bolt carrier is the piston sleeve. It is more correct to call it an “internal piston” system." |
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Six of one half dozen of another. Personal preference. I have both. Honestly, I prefer the adams arms "piston system" upper. Why? Well, because much time in the military spent cleaning M16's I was tired of dealing with the mess. So I decided to try a "piston system". The Adams is definitely not cheap but it's worth it IMO. Zero issues with it thus far.
Both systems are good. They work. In the end that's what truly matters, reliability. The rest is all personal preference. |
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just makes sense....less dirt, less need for oil, more force directed rearward with a solid rod than air = more reliable. why does a 7 inch SBR piston upper works better than a 7 inch gas tube upper? even if they are both equally reliable....the piston still has more advantage. for example less oil needed and less gas in your face and where has this been proven a novelty? where is your source or study? there may be I just didn't see one I base it on my use of my 8 ARs. 4 are pistons and others have gas tubes. And I would take my Sig or CMMG or POF over any of my other gas driven ARs. The idea that shooting 500 rounds through one with a gas tube requires oil and is filthy is just one of the reasons why Your study and source is your 8 ARs? The piston AR has never been proven to be more reliable. It has, however, been proven to be heavier, have more moving parts, and have more individually specific parts to its model. Not knocking it. I base my source on my 8 ARs, just like you. All of them DI. I also base it on the vast number of DIs in use. The source and studies you seek are actually on this site, and they may or may not be around shortly to post in this thread, Nothing wrong with piston, but don't say they are more reliable because your parts list "makes sense" |
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Quoted: no gas in the face when suppressed That does not change with a piston. What does change is the time it takes for the action to cylcle and release that gas. For a piston gun its might be a little slower compared to a non modified "DI" carbine. Add a heavy buffer or a selectable gas system and then the pistons very slight edge will be lost. A selectable gas system will be a shitload better than a piston. I bought into the piston thing when they first came out, put one through its paces, burned a barrel or two, posted about it, broke a ton of parts shooting more ammo through one than prob 95% of shooters will ever attempt. Of all the subjective "betters" commonly claimed, they have never panned out when run more than bench session worth of ammo. I went back to DI, run corrosive ammo on a m16 and dont clean a 10" barrel, it works fine w/o piston magic. |
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can you explain the efficiency, like with numbers? And could you also explain what the two hole on the side of the BC are for? Quoted:
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anytime you have less crap coming back in you've made it more efficient and to argue otherwise is stupid. And could you also explain what the two hole on the side of the BC are for? They're for adding oil between cleanings, much like adding oil between flushings to an extremely inefficient motor that burns it 
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do a test yourself
shoot a few hundred rounds from a GP and one with a gas tube then tell me which one needs more oil and more cleaning then take out the bcg and hold both in your hand and tell me which has more heat then take a 7.5 inch upper (GP and tube) and shoot cheap under powered ammo through it...see which fails then shoot suppressed with each do 200 rds rapid fire or FA in each and tell me which you would want you cant compare the first piston systems with the ones now....they have been improved a lot since then if you want to do that then compare them with the DI ones when they first came out in the 60s more parts doesn't mean is more likely to fail the only down side to the piston is that it has proprietary parts and is slightly heavier which isn't an issue for most applications of the weapon and most men FOR ME...If given the choice in a combat scenario when many rounds will be fired, in harsh environments, where I might use a suppressor, and I don't want to oil my weapon often - the piston is my choice. |
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Some manufacturers make quality versions, but if you want a true piston gun, get an AK, SIG 556, or SCAR.
This is why I am asking. I own a couple of DI ARs and a couple of AKs, and I am planning to get a Sig556 soon, BUT am also considering picking up a Ruger SR-556 and SR-762 (matched set) as soon as the SR-762 actually hits the shelves - apparently it isn't available in New England yet. The Rugers are 'designed' to be piston guns, but also share the basic AR design. |
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This is why I am asking. I own a couple of DI ARs and a couple of AKs, and I am planning to get a Sig556 soon, BUT am also considering picking up a Ruger SR-556 and SR-762 (matched set) as soon as the SR-762 actually hits the shelves - apparently it isn't available in New England yet. The Rugers are 'designed' to be piston guns, but also share the basic AR design. Quoted:
Some manufacturers make quality versions, but if you want a true piston gun, get an AK, SIG 556, or SCAR.
This is why I am asking. I own a couple of DI ARs and a couple of AKs, and I am planning to get a Sig556 soon, BUT am also considering picking up a Ruger SR-556 and SR-762 (matched set) as soon as the SR-762 actually hits the shelves - apparently it isn't available in New England yet. The Rugers are 'designed' to be piston guns, but also share the basic AR design. the ergonomics of the AK aren't as good as an AR AR is a better weapon than a Sig556 and would rather have a Sig516 (or LWRC) SCAR would be the rifle I would get if I didn't go with a AR piston. I just don't like the charging handle |
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They're for adding oil between cleanings, much like adding oil between flushings to an extremely inefficient motor that burns it Quoted:
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anytime you have less crap coming back in you've made it more efficient and to argue otherwise is stupid. And could you also explain what the two hole on the side of the BC are for? They're for adding oil between cleanings, much like adding oil between flushings to an extremely inefficient motor that burns it Please tell me that you're being sarcastic... 
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| If I could afford one I would have a SCAR, I think they are a superior weapon. But my DI AR gets the job done. Ultimately the 10 series is a better weapon all around, if you can afford to shoot it. Shoot your weapon, clean it and be happy with it if it does not give you problems. I'm not going to get caught up in the AR hype that some folks believe in, just because they have an unlimited budget for their hobby. Or they just spend to much $$$ on it, I'm just not that wrapped up into it. |
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the ergonomics of the AK aren't as good as an AR AR is a better weapon than a Sig556 and would rather have a Sig516 (or LWRC) SCAR would be the rifle I would get if I didn't go with a AR piston. I just don't like the charging handle Quoted:
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Some manufacturers make quality versions, but if you want a true piston gun, get an AK, SIG 556, or SCAR.
This is why I am asking. I own a couple of DI ARs and a couple of AKs, and I am planning to get a Sig556 soon, BUT am also considering picking up a Ruger SR-556 and SR-762 (matched set) as soon as the SR-762 actually hits the shelves - apparently it isn't available in New England yet. The Rugers are 'designed' to be piston guns, but also share the basic AR design. the ergonomics of the AK aren't as good as an AR AR is a better weapon than a Sig556 and would rather have a Sig516 (or LWRC) SCAR would be the rifle I would get if I didn't go with a AR piston. I just don't like the charging handle Please explain why you'd rather have a 516 vs a 556. |
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If I could afford one I would have a SCAR, I think they are a superior weapon. But my DI AR gets the job done. Ultimately the 10 series is a better weapon all around, if you can afford to shoot it. Shoot your weapon, clean it and be happy with it if it does not give you problems. I'm not going to get caught up in the AR hype that some folks believe in, just because they have an unlimited budget for their hobby. Or they just spend to much $$$ on it, I'm just not that wrapped up into it. Of you knew what the military knows you'd have reservations about the SCAR. |
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Please explain why you'd rather have a 516 vs a 556. I had a 556 SWAT and while it was 100% reliable (un)suppressed, I couldn't get past that I couldn't get an iron sight setup to work for me. AR irons and a cheek riser sucked. The stock irons and SIG diopter rear sucked. (Gas block/front sight was canted, sent in for repair, and sent back unaltered.) Nobody I let shoot it, wanted to shoot it again and complained it was too front heavy. And I didn't like the 556 adjustable stock, or the AR conversion or the grip and location of the safety. Can't say any of that with any AR I have owned. |
| i have a bunch of di ars one piston ar (stag 8) and a couple aks. my piston gun runs much cleaner and its the one i use with my cmmg .22 conversion because i can shut the gas block off and keep the dirty .22 shit out of my reciever. my piston gun is a little heavier but its 100% rock solid. also to note the back of the bolt carrier has small "pads" on it to prevent moving around in the buffer tube |
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Of you knew what the military knows you'd have reservations about the SCAR. Quoted:
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If I could afford one I would have a SCAR, I think they are a superior weapon. But my DI AR gets the job done. Ultimately the 10 series is a better weapon all around, if you can afford to shoot it. Shoot your weapon, clean it and be happy with it if it does not give you problems. I'm not going to get caught up in the AR hype that some folks believe in, just because they have an unlimited budget for their hobby. Or they just spend to much $$$ on it, I'm just not that wrapped up into it. Of you knew what the military knows you'd have reservations about the SCAR. What does the military know about the SCAR? |
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Idk I have owned both. I prefer DI.
Anyone who thinks the pistons dont get as dirty as DI(excluding the self cleaners) does not have enough experience to speak on the differences.The DI stays in the receiver and requires minimal lubing when using proper ammo, the piston gets gobed up in a much smaller area, and causes massive amounts of heat, and like a poster before said the self cleaners self clean all over you.. I have done rapid fire with many rounds with each...the piston guns Ive tried get too hot to operate effectively before the DI will ever get too dirty to shoot, if properly lubed from the beginning. I have a running test going actually... On one of my DI AR pistols...I lubed it up and went shooting a few weeks ago, I said I will not clean/lube it until it malfunctions...my round count is at 720 so far. |
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It breaks, an FN can't make spare parts fast enough. Bolts and stocks. They also post sparks from the gas block, break optics and the precision variant isn't so precise. Do you have a source? I'd like to read up on it if so, as I am in the market for one. Why is the .mil still buying if they suck so bad? |
| Good googling will turn up the warning from Crane about the optics failing but most of my information is straight from maintainers or people who tested it in the SOF community. The 16 was dropped because it wasn't better than the M4. The 17 stays because there is nothing similar in service so it's quirks are much more tolerable. And because it's fucking cool! The 20 I don't know much about except that everyone I know wanted to keep the Mk12 instead but some program office wasn't having it. Rumor is the 20 isn't all that accurate. |
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Good googling will turn up the warning from Crane about the optics failing but most of my information is straight from maintainers or people who tested it in the SOF community. The 16 was dropped because it wasn't better than the M4. The 17 stays because there is nothing similar in service so it's quirks are much more tolerable. And because it's fucking cool! The 20 I don't know much about except that everyone I know wanted to keep the Mk12 instead but some program office wasn't having it. Rumor is the 20 isn't all that accurate. The reading I have done on the subject seemed to conclude that the Mk16 was not fielded because it did not offer enough advantage over the M4 to justify the cost of all out M4 replacement. The dust test results indicate that the M4 competitors experienced substantially fewer malfunctions than the M4 did, but in the end (begin conjecture) the top officials said, "yeah the M4 performed worse than the rest, but it's still good enough." (end conjecture) So it would appear that the Mk16 is better, just not "better enough." I can't speak to the accuracy of the Mk20. Is the bolt breakage specific to the Mk17 or has it been problematic in the 16 as well? What breaks; the lugs? The body? |
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Bolts were a Mk16 issue for sure, not sure about the 17. Stocks are both. The 16 wasn't an improvement on the M4 in a notable way and traded problems we know for problems yet tp be understood.The dust test was a clusterfuck. They counted failures of the burst mechanism to fire 3 rounds at a time as a failure.
I have yet to meet someone who liked the SCAR in military usage except for a Specialist at 2/75 that wasn't issued one. He was holding one as he spoke. ETA: The only bolt failure mode I've discussed with people is a bolt broken in half. I'd expect given its design it has similar lug breakage issues to an M4. If they'd licensed the KAC E3 bolt, used metal more in the stock and a long stroke piston I suspect the rifle would work better. |
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I feel like its a non-issue..
For me it comes down to weight mostly. DI is lighter. The reliability and wear is going to be the same given quality components in each. I like my 716 (piston ar10) for the fact that I have plans for a suppressor and pistons are easier to find a gas block with "settings" and for suppressed shooting it is cleaner. However I have DI AR15s that I like just as much.. just different applications. The only other factor would be parts availability. DI AR15s are EVERYWHERE. |
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Six of one half dozen of another. Personal preference. I have both. Honestly, I prefer the adams arms "piston system" upper. Why? Well, because much time in the military spent cleaning M16's I was tired of dealing with the mess. So I decided to try a "piston system". The Adams is definitely not cheap but it's worth it IMO. Zero issues with it thus far. Both systems are good. They work. In the end that's what truly matters, reliability. The rest is all personal preference. I hear what your saying but... I'll go 500 to 1000 rounds between cleaning, if even then, and it's just not that darn dirty when I do clean a DI AR. Granted; I only shoot Federal, AE, PMC, and Prvi ammo, so maybe it's extra clean. I don't see the point of or the necessity of cleaning an AR with a toothbrush every 200 rounds... If you like Piston's then fine, they are ok, but it's not like the DI is so dirty and disgusting that warrants the reasoning behind the Piston system of "I love my piston because the DI gets too dirty"... I know that is not what your saying OIF3vetk9, but others sure are implying that stupid BS... |
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I hate "___________vs.__________" threads.
D.I. is a piston system, the bolt is the piston. It places the thrust of the action concentric to the bore line, removing the barrel deflection of the piston systems of the past. In order to move a off center piston, gas pressure to it's front face must overcome the bolt lock/spring pressure. When the piston is over the bore, the barrel is deflected downward as the pressure builds. As seen in the AK series weapons. When the piston return forward the barrel is deflected downward (this is not an issue in semiautomatic fire). The deflection imparted on the barrel is never consistent, and this degrades accuracy. In the AR piston modification, this deflection is evidenced at the other end of the piston rod by bolt carrier deflection, and the subsequent wear on the receiver extension. This is a concept design I did to try and negate the piston issue 
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A firearm designed for piston operation like an AK has provision to deal with the stresses and motions of the B/BC. Generally this takes the form of a B/BC riding on "rails". Piston operated actions also put the recoil spring in opposition to the piston or at some intermediate location so as to reduce the rotational forces. Generally the moving parts contact points are steel-on-steel to stand up to wear vs a steel-on-aluminum or similar situation. The AR15 platform has neither of those, as it was not designed for piston operation. The general approach has been to enlarge the contact areas between the BC and the receiver and receiver extension/buffer tube to try to limit the amount of wear. Also changing the parts fit a little to reduce the twisting forces put on the bolt. Quoted:
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although AKs sure seem to like them... A firearm designed for piston operation like an AK has provision to deal with the stresses and motions of the B/BC. Generally this takes the form of a B/BC riding on "rails". Piston operated actions also put the recoil spring in opposition to the piston or at some intermediate location so as to reduce the rotational forces. Generally the moving parts contact points are steel-on-steel to stand up to wear vs a steel-on-aluminum or similar situation. The AR15 platform has neither of those, as it was not designed for piston operation. The general approach has been to enlarge the contact areas between the BC and the receiver and receiver extension/buffer tube to try to limit the amount of wear. Also changing the parts fit a little to reduce the twisting forces put on the bolt. Perfectly said sir. |
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Perfectly said sir. Quoted:
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although AKs sure seem to like them... A firearm designed for piston operation like an AK has provision to deal with the stresses and motions of the B/BC. Generally this takes the form of a B/BC riding on "rails". Piston operated actions also put the recoil spring in opposition to the piston or at some intermediate location so as to reduce the rotational forces. Generally the moving parts contact points are steel-on-steel to stand up to wear vs a steel-on-aluminum or similar situation. The AR15 platform has neither of those, as it was not designed for piston operation. The general approach has been to enlarge the contact areas between the BC and the receiver and receiver extension/buffer tube to try to limit the amount of wear. Also changing the parts fit a little to reduce the twisting forces put on the bolt. Perfectly said sir. So, on current (not initial) piston AR15s there is still excessive wear on the receiver or BCG? Or has this issue been corrected? If it has been corrected than the piston is a better system because of all the added benefits a piston has. Also the FAL has a spring on the piston and that works fine. The only concern would be wear on the aluminum receiver. I believe those issues have been fixed. Also how would a heavier buffer affect the wear? I think it would make less. |
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So, on current (not initial) piston AR15s there is still excessive wear on the receiver or BCG? Or has this issue been corrected? If it has been corrected than the piston is a better system because of all the added benefits a piston has. Also the FAL has a spring on the piston and that works fine. The only concern would be wear on the aluminum receiver. I believe those issues have been fixed. Also how would a heavier buffer affect the wear? I think it would make less. Quoted:
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although AKs sure seem to like them... A firearm designed for piston operation like an AK has provision to deal with the stresses and motions of the B/BC. Generally this takes the form of a B/BC riding on "rails". Piston operated actions also put the recoil spring in opposition to the piston or at some intermediate location so as to reduce the rotational forces. Generally the moving parts contact points are steel-on-steel to stand up to wear vs a steel-on-aluminum or similar situation. The AR15 platform has neither of those, as it was not designed for piston operation. The general approach has been to enlarge the contact areas between the BC and the receiver and receiver extension/buffer tube to try to limit the amount of wear. Also changing the parts fit a little to reduce the twisting forces put on the bolt. Perfectly said sir. So, on current (not initial) piston AR15s there is still excessive wear on the receiver or BCG? Or has this issue been corrected? If it has been corrected than the piston is a better system because of all the added benefits a piston has. Also the FAL has a spring on the piston and that works fine. The only concern would be wear on the aluminum receiver. I believe those issues have been fixed. Also how would a heavier buffer affect the wear? I think it would make less. none, not on any lwrc rifles I have |
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I have shot pistons such as the Stag 8,Adams arms conversion on a LMT and LWRC. I didn't shoot them enough to say they are better then a DI gun. The worse shooting gun in my opinion was the LWRC due to weight and the type of recoil due to the piston rod. I like the DI guns for weight and felt recoil, very smooth. Any weapon can have issues piston or DI but many people don't shoot there rifles hard even if the take a class once a year due to cost and ammo.
I had an issue with my Colt 6920 at the 4th day of a five day class. I did not clean my rifle but only lubed as needed. 
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| I have not had a problem with my DI AR15s and issued M16s. I do not own a piston weapon, but on an impulse I almost bought a Sig516 this weekend at the gun show. Glad I resisted the impulse. As I though about it, I decided I would buy a piston weapon when Daniel Defense decided to make one, and not before then. |
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Quoted:
So, on current (not initial) piston AR15s there is still excessive wear on the receiver or BCG? Or has this issue been corrected? Quoted:
So, on current (not initial) piston AR15s there is still excessive wear on the receiver or BCG? Or has this issue been corrected? It's not possible to correct the fundamental issues as long as you stay with the AR15 receivers, BCG etc. You can mitigate some of the damage but the underlying issues cannot be changed. If it has been corrected than the piston is a better system because of all the added benefits a piston has. What are those added benefits exactly, and what about the detriments? The idea that the AR15 is somehow deficient or defective and needs to be fixed or upgraded with a piston is wrong. Also the FAL has a spring on the piston and that works fine. Essentially all short stroke operated arms have a spring on the piston, dunno what difference that makes. The only concern would be wear on the aluminum receiver. I believe those issues have been fixed. Also how would a heavier buffer affect the wear? I think it would make less. I don't see how buffer weight would have any influence at all on carrier tilt issues. |
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