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Posted: 10/21/2011 12:27:32 PM EDT
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I have contacted a few companies concerning purchasing a few SBRs (.223/5.56). When the discussion comes up about full auto 11 inch barreled rifles some companies are reluctant to build one with a piston system stating they are concerned about reliability of a piston system on a full auto weapon. Other companies have no problem building what we want.
I have a personal LWRC (semi-auto of course) that I love and have had no problem with. My experience with the piston systems in minimal. I would like to hear from those with better knowledge about any concerns that there would be concerning this set up. Any advice/experience/knowledge would be appreciated. Thanks, JCrowder |
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Hey there,
I recently purchased an Adams Arms PDW Elite Upper for my Full Auto lower. It works !!!! At first, the timing was off, I should say, it ran really slow. Then I remembered, I was using a heavy 9mm buffer to slow down the cycle rate of my 11.5" upper. Once I switch it to a standard H buffer, it ran normal. I also had a cycling problem in full auto when I used my suppressor. Turns out, I had to switch to the second setting on the piston. Once I got over the user problems, it ran the way it was intended, without issues and very reliable !! Oh, I almost forgot, it runs without a special muzzle break, standard bird cage !! Overall, Adams Arms makes an awesome product, Grade A + !! http://i171.photobucket.com/albums/u315/Reyman_2007/AR%20M16%20FRANKFORD%20ARSENAL/MicroM16woSUPP.jpg http://i171.photobucket.com/albums/u315/Reyman_2007/AR%20M16%20FRANKFORD%20ARSENAL/MicroM16wSUPP1.jpg http://i171.photobucket.com/albums/u315/Reyman_2007/AR%20M16%20FRANKFORD%20ARSENAL/MicroM16SitesR.jpg http://i171.photobucket.com/albums/u315/Reyman_2007/AR%20M16%20FRANKFORD%20ARSENAL/MicroM16SitesL.jpg I'll try to monitor this post over the weekend to answer an questions you all may have. Enjoy |
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I run a PWS 10" upper just fine. No issues at all with over 30K rounds through it.
here |
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I had an Adams on an 8" 5.45 upper using an MGI lower and RDIAS. Running 45 round mags and 77 round drums. I recently noticed the oprod is bent pretty bad. Went back to DI. This is one of the issues with pistons, using heavy buffers puts more stress on the components like the op rod, gas block and impact lug on the carrier. Although, I haven't tried a PWS. Being long stroke, it may not have the same issues. Too heavy a buffer on DI and worse thing that will happen is it won't cycle.
Also have an Ares kit but not as many rounds through it. The Ares doesn't have the meloniting so it got rusted up with 5.45 while the Adams handled that well. Tried a LWRC and in FA it shot way too fast. Over 1k rounds per minute. This was a long time ago. Haven't tried an LWRC in at least t yrs. The recoil is definitely worse on all 3 of the above compared top regular DI. Can easily feel the difference in FA. |
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Hey there, I recently purchased an Adams Arms PDW Elite Upper for my Full Auto lower. It works !!!! At first, the timing was off, I should say, it ran really slow. Then I remembered, I was using a heavy 9mm buffer to slow down the cycle rate of my 11.5" upper. Once I switch it to a standard H buffer, it ran normal. I also had a cycling problem in full auto when I used my suppressor. Turns out, I had to switch to the second setting on the piston. Once I got over the user problems, it ran the way it was intended, without issues and very reliable !! Oh, I almost forgot, it runs without a special muzzle break, standard bird cage !! Overall, Adams Arms makes an awesome product, Grade A + !! http://i171.photobucket.com/albums/u315/Reyman_2007/AR%20M16%20FRANKFORD%20ARSENAL/MicroM16woSUPP.jpg http://i171.photobucket.com/albums/u315/Reyman_2007/AR%20M16%20FRANKFORD%20ARSENAL/MicroM16wSUPP1.jpg http://i171.photobucket.com/albums/u315/Reyman_2007/AR%20M16%20FRANKFORD%20ARSENAL/MicroM16SitesR.jpg http://i171.photobucket.com/albums/u315/Reyman_2007/AR%20M16%20FRANKFORD%20ARSENAL/MicroM16SitesL.jpg I'll try to monitor this post over the weekend to answer an questions you all may have. Enjoy That's a beautiful setup! |
| I have a Model 1 upper with their chrome lined 11.5" bbl. I installed an Osprey gas piston kit. I shoot it full auto. The only issue I had was that the Osprey supplied handguard had very few holes for cooling (I believe they have more holes now) so it got hotter. I installed a MI handguard designed for the Osprey kit...keeps much cooler now. Oh, functioning is flawless. |
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Some guns, LWRC included, have issues with auto fire that they don't have with semi. For one thing, a lot of your cmmercial DI ARs would run poorly if they were autos. You just don't experience the issues on semi guns. Brother you should stop making blanket statements. This is Chris' upper on an FA lower with no other changes and watch how it runs. I know its only one mag, but it seems to be doing just fine to me. [youtube]http://www.youtube.com/watch?v=TpsPkZRMf44[/youtube] |
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Damn dude, 30 rounds without failure! Wow!
LWRCs have some sort of piston cup that is developing a rep for breaking in auto gins but not semi guns. Certain other rifle types are known for issues on auto that don't occur on semi, to include the M4 and Sig 552. The point is that automatic weapons are more finicky than semiautomatic weapons. |
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I have contacted a few companies concerning purchasing a few SBRs (.223/5.56). When the discussion comes up about full auto 11 inch barreled rifles some companies are reluctant to build one with a piston system stating they are concerned about reliability of a piston system on a full auto weapon. Other companies have no problem building what we want. I have a personal LWRC (semi-auto of course) that I love and have had no problem with. My experience with the piston systems in minimal. I would like to hear from those with better knowledge about any concerns that there would be concerning this set up. Any advice/experience/knowledge would be appreciated. Thanks, JCrowder POF builds kick ass piston operated FA. |
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Damn dude, 30 rounds without failure! Wow! LWRCs have some sort of piston cup that is developing a rep for breaking in auto gins but not semi guns. Certain other rifle types are known for issues on auto that don't occur on semi, to include the M4 and Sig 552. The point is that automatic weapons are more finicky than semiautomatic weapons. I beg to differ... We ship a sh?t ton of F/A SBRs over-seas and to many beltway agencies and I am yet to hear of any issue related to the piston cup or F/A operation. So please provide supporting evidence to back up your statement. |
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At that very shoot I watched the 10.5 A2 run through about 2000rds full auto about half of that suppressed, no breakages of piston cups or springs or anything of the sort, none. I put about 300rds through it myself. The thing ran like a frickin singer sewing machine. I would like to see his proof too because I know he is full of shit.
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Damn dude, 30 rounds without failure! Wow! LWRCs have some sort of piston cup that is developing a rep for breaking in auto gins but not semi guns. Certain other rifle types are known for issues on auto that don't occur on semi, to include the M4 and Sig 552. The point is that automatic weapons are more finicky than semiautomatic weapons. I beg to differ... We ship a sh?t ton of F/A SBRs over-seas and to many beltway agencies and I am yet to hear of any issue related to the piston cup or F/A operation. So please provide supporting evidence to back up your statement. The reason why I posted that vid is because that things was stroking at a clean 800rds a minute. Hold you pac timer up to the speakers if you don't believe me. No overgassing issues or anything of the sort. |
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Damn dude, 30 rounds without failure! Wow! LWRCs have some sort of piston cup that is developing a rep for breaking in auto gins but not semi guns. Certain other rifle types are known for issues on auto that don't occur on semi, to include the M4 and Sig 552. The point is that automatic weapons are more finicky than semiautomatic weapons. I beg to differ... We ship a sh?t ton of F/A SBRs over-seas and to many beltway agencies and I am yet to hear of any issue related to the piston cup or F/A operation. So please provide supporting evidence to back up your statement. Search on the site where I found the discussion of issues/pictures of broken spring cups isn't working for me right now. I will try to get you the pictures as evidence. How many is a shit ton? 2,000 plus a month? |
| There is like one picture and its always posted up when people try to discredit LWRCI. Sad thing is the original poster of that picture also stated the rifle was still running and explained that LWRCI also gave him replacement parts and in no way did he feel that this hindered the company's reputation nor did it change his opinion of the rifle. If I remember correctly he also stated that he ran the parts long past the recommended interval. With probably close to 100K rifles out there, if it was really a problem for LWRCI you would hear about it a whole lot more. |
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I've now seen a half a dozen people claim to have it happen and that they've seen it only in auto with a suppressor. I doubt all 100,000 are auto guns fired suppressed.
I don't care to pick on LWRC because I'm sure it's an easy fix––probably a small piece of some supermetal and they are good to go. The point is things happen in automatic weapons that don't happen in other weapons and without testing it's hard to determine what. |
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I've now seen a half a dozen people claim to have it happen and that they've seen it only in auto with a suppressor. I doubt all 100,000 are auto guns fired suppressed. I don't care to pick on LWRC because I'm sure it's an easy fix––probably a small piece of some supermetal and they are good to go. The point is things happen in automatic weapons that don't happen in other weapons and without testing it's hard to determine what. How is there anything different occurring in a full auto AR's upper half vs a semi auto of the same type aside from the accumulation and dissipation of more heat as more rounds are being fired per trigger pull? The weapon's action itself and all related assemblies such as the piston/op-rod and spring and cup on the LWRC you mention are all doing the same thing as each round is fired whether it is semi auto or full auto. I do agree that a suppressed weapon, due to the greatly increased gas port pressure and other gas dynamics changed due to the addition of the suppressor will exhibit changed function and forces will be exerted on internal components that wouldn't normally exist. I believe this is the cause of the spring cup fractures that you are talking about. It is merely the piston/op-rod being driven back with far greater force due to the suppressor than it was ever designed for. |
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Damn dude, 30 rounds without failure! Wow! LWRCs have some sort of piston cup that is developing a rep for breaking in auto gins but not semi guns. Certain other rifle types are known for issues on auto that don't occur on semi, to include the M4 and Sig 552. The point is that automatic weapons are more finicky than semiautomatic weapons. You've mentioned that several times before. I've heard of it happeneing only twice. That doesn't exactly qaulify as "developing a rep." I personally know folks who run LWRCi uppers on full auto lowers, and they work just fine (through thousands of rounds), so long as you're using the proper buffer. |
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Hey there, I recently purchased an Adams Arms PDW Elite Upper for my Full Auto lower. It works !!!! At first, the timing was off, I should say, it ran really slow. Then I remembered, I was using a heavy 9mm buffer to slow down the cycle rate of my 11.5" upper. Once I switch it to a standard H buffer, it ran normal. I also had a cycling problem in full auto when I used my suppressor. Turns out, I had to switch to the second setting on the piston. Once I got over the user problems, it ran the way it was intended, without issues and very reliable !! Oh, I almost forgot, it runs without a special muzzle break, standard bird cage !! Overall, Adams Arms makes an awesome product, Grade A + !! http://i171.photobucket.com/albums/u315/Reyman_2007/AR%20M16%20FRANKFORD%20ARSENAL/MicroM16woSUPP.jpg http://i171.photobucket.com/albums/u315/Reyman_2007/AR%20M16%20FRANKFORD%20ARSENAL/MicroM16wSUPP1.jpg http://i171.photobucket.com/albums/u315/Reyman_2007/AR%20M16%20FRANKFORD%20ARSENAL/MicroM16SitesR.jpg http://i171.photobucket.com/albums/u315/Reyman_2007/AR%20M16%20FRANKFORD%20ARSENAL/MicroM16SitesL.jpg I'll try to monitor this post over the weekend to answer an questions you all may have. Enjoy Normally i'm kinda meh about SBRs, but that straight up made me hard. |
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Accumulation of heat is my assumption for spring cup failures though auto will in all rifles bring out timing, buffering and spring rate issues like bolt bounce which are essentially unknown in semi. I'll agree with the second parts, I have no first hand experience with an lwrc so can't comment on the cup. I'd give the nod to an Adams arms setup as mine has run awesome. I've had only 3 jams out of 1500 rounds and one was from a popped primer of m855 that got stuck in the bolt, the other two were from doing mag dumps full auto but that was breaking it in. My setup is a 7.5 by the way 
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Damn dude, 30 rounds without failure! Wow! LWRCs have some sort of piston cup that is developing a rep for breaking in auto gins but not semi guns. Certain other rifle types are known for issues on auto that don't occur on semi, to include the M4 and Sig 552. The point is that automatic weapons are more finicky than semiautomatic weapons. You've mentioned that several times before. I've heard of it happeneing only twice. That doesn't exactly qaulify as "developing a rep." I personally know folks who run LWRCi uppers on full auto lowers, and they work just fine (through thousands of rounds), so long as you're using the proper buffer. I can attest to this, at least to the sampling that I ersonally own. I have never had a failure of any of my LWRC uppers when mated with my FA Colt SP1 and fired full-auto. My older LWRC upper is a 10.5" M6A1 that has over 14k rounds through it (one of these days I'll add up how many rounds were fired on FA). I've done multiple mag dumps with this combination without any failure (using Wolf ammo, no less). Full-auto fire is harder on parts, but I have never heard any of the well-made Piston or DI guns ever having consistent failures with this type of use. It seems that a lot of people likes to take a sampling of one or two and apply it to the thousands that are in use. Here is a 50-round dump. The first mag was a 30-round dump into UCOM and the second was a 20-round dump into the face at about 7-yards: LWRC Full-auto mag dump Here is the target: 
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I have contacted a few companies concerning purchasing a few SBRs (.223/5.56). When the discussion comes up about full auto 11 inch barreled rifles some companies are reluctant to build one with a piston system stating they are concerned about reliability of a piston system on a full auto weapon. Other companies have no problem building what we want. I have a personal LWRC (semi-auto of course) that I love and have had no problem with. My experience with the piston systems in minimal. I would like to hear from those with better knowledge about any concerns that there would be concerning this set up. Any advice/experience/knowledge would be appreciated. Thanks, JCrowder Here two videos of my Colt 901 firing with a POF 7.25 416 upper on it. http://www.youtube.com/watch?v=n5Bg8fkC89U http://www.youtube.com/watch?v=hNawF1D4Iws We had no problems that day with the POF 416 Upper. We put 500 rounds through it. Dane |
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i have some limited full auto experience with my various LWRC uppers and my SOT's buddies full auto lowers.
when we go out shooting i'll put my 18" M6A3 LWRC upper on his FA lower and fire away for 100's of rounds at a time. i've put over 1000 rounds of F/A fire thru it with zero malfunctions but i will be taking my rail off tonight to look at the piston cup and see how it looks. we we using the vltor A5 buffer system too. it slowed the cycle rate to that about equal to a 20" A2 Di rifle. i have a 12.5" LWCR m6a3 upper that ran just fine as well on F/A with a carbine stock. i will admit this barrel had been cut back from something longer and we opened the gas port until it would cycle 100% with a wide range of mil spec down to silver bear. my only problem was with a 10.5 inch LWRC m6A1 that would not run on FA 100% and would short stroke once in awhile, not enough gas i am guessing. |
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I've now seen a half a dozen people claim to have it happen and that they've seen it only in auto with a suppressor. I doubt all 100,000 are auto guns fired suppressed. I don't care to pick on LWRC because I'm sure it's an easy fix––probably a small piece of some supermetal and they are good to go. The point is things happen in automatic weapons that don't happen in other weapons and without testing it's hard to determine what. How is there anything different occurring in a full auto AR's upper half vs a semi auto of the same type aside from the accumulation and dissipation of more heat as more rounds are being fired per trigger pull? The weapon's action itself and all related assemblies such as the piston/op-rod and spring and cup on the LWRC you mention are all doing the same thing as each round is fired whether it is semi auto or full auto. I do agree that a suppressed weapon, due to the greatly increased gas port pressure and other gas dynamics changed due to the addition of the suppressor will exhibit changed function and forces will be exerted on internal components that wouldn't normally exist. I believe this is the cause of the spring cup fractures that you are talking about. It is merely the piston/op-rod being driven back with far greater force due to the suppressor than it was ever designed for. If I have an upper that only will run well in Semi, Its broke and somthing is wrong with it. Full auto fire may cause a stoppage sooner just because you are getting hotter and dirtier quicker. If the stoppage is because of the upper not being in spec well that will eventually catch up to you in semi also. Suppressed weapons are a whole nother ball game. Edit to add. Im my experienc piston uppers run much longer in full auto before "I am dirty and hot" hicup happens which always seems to be in the 6th mag or so in the DI gun that I am issued. |
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Accumulation of heat is my assumption for spring cup failures though auto will in all rifles bring out timing, buffering and spring rate issues like bolt bounce which are essentially unknown in semi. Could you please give us some info on this? I mean, if your going to knock the system you could at lease give us some research you did to draw this conclusion. |
This is a friend's 5.45 upper. He cut the barrel down to 10.5" and added a Spike's SAR rail. It was run on a postie lower. I believe he had 2-3 tins run through it when it did this. I was at the range with him at the time. IT was running fine then became a single shot. Not sure how indicative of piston problems it is but to me it is demonstrative of how far out in left field that problems can arise when you start adding parts to something that was simpler to begin with. |
we have ran the living snot out of both a PWS Diablo, and a version of the Mk110 from PWS for the simple purpose of trying to melt one down. Both systems ran great with zero problems. We figured we put around 1100 rounds through both with zero malfunctions. The Mk110 was suppressed. We all got bored from loading magazines and decided to play with night vision instead. 
Yes we suck at melting guns down. 
I am real impressed with the PWS Product! |
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http://i15.photobucket.com/albums/a381/yekimak/338611_310047772344056_100000165064115_1530468_1602183164_o.jpg This is a friend's 5.45 upper. He cut the barrel down to 10.5" and added a Spike's SAR rail. It was run on a postie lower. I believe he had 2-3 tins run through it when it did this. I was at the range with him at the time. IT was running fine then became a single shot. Not sure how indicative of piston problems it is but to me it is demonstrative of how far out in left field that problems can arise when you start adding parts to something that was simpler to begin with. Last I checked all ARs have a gas block. It looks like this one met its temperature limit. How is this a piston problem? I bet you whatever caused this would have melted a gas tube long before this occurred. |
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Damn dude, 30 rounds without failure! Wow! LWRCs have some sort of piston cup that is developing a rep for breaking in auto gins but not semi guns. Certain other rifle types are known for issues on auto that don't occur on semi, to include the M4 and Sig 552. The point is that automatic weapons are more finicky than semiautomatic weapons. typical arfcom piston bashing. proof? |
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He has none. This was asked several times with the same respoinse if any. I watched a select fire M6A2 run through 2000 rds in a couple hours about half suppressed and there were no parts failures of any kind. This was without cleaning either, just a spray of EWL here and there.
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Damn dude, 30 rounds without failure! Wow! LWRCs have some sort of piston cup that is developing a rep for breaking in auto gins but not semi guns. Certain other rifle types are known for issues on auto that don't occur on semi, to include the M4 and Sig 552. The point is that automatic weapons are more finicky than semiautomatic weapons. typical arfcom piston bashing. proof? |
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http://i15.photobucket.com/albums/a381/yekimak/338611_310047772344056_100000165064115_1530468_1602183164_o.jpg This is a friend's 5.45 upper. He cut the barrel down to 10.5" and added a Spike's SAR rail. It was run on a postie lower. I believe he had 2-3 tins run through it when it did this. I was at the range with him at the time. IT was running fine then became a single shot. Not sure how indicative of piston problems it is but to me it is demonstrative of how far out in left field that problems can arise when you start adding parts to something that was simpler to begin with. Last I checked all ARs have a gas block. It looks like this one met its temperature limit. How is this a piston problem? I bet you whatever caused this would have melted a gas tube long before this occurred. When I said it had 2-3 tins through it, I meant over the life of the gun, sorry I was not clear on that. It broke after just about 2-3 magazines that day. It went down pretty early on. Gas tubes do get hot and they can burst, but they do also cool fast. Yes, most all AR's have gas blocks, not all AR's have the same forces on the blocks. On a short piston system the block gets it twice per cycle. Once when gas pushes the piston, and again when the op rod comes back home. It was not a temperature issue that caused that break, it was most likely a hidden defect and not anything inherent in the design. As I said before I just believe that it is demonstrative of how out in left field things can come at you. While I have heard of and seen video of burst tubes, I ain't ever seen a DI gas block crack off from use. |
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Something is wrong with your DI rifle. I have a little bit of experience with M4A1s and they should run ten mags back to back without issue. Funny, if he was shooting a piston gun you would be claiming that it is a design or manufacturing flaw even though it is based on a sampling of one. But since it's a DI rifle, it must be a freak of nature. You're integrity and opinoin is about as useful as teets on a boar!! 
NOTE: Unlike Mr. Jack here, I am not making any kind of ASSumption that the issue is with the design or the manufacturer. I cannot, in good conscience, make such a wild ASSumption without a larger sampling or firsthand knowledge. |
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