Adams Arms Piston Review

Murdoc has written a review of the Adam Arms retrofit piston system for the AR-15 for Guns and Hunting.

The new Adams Arms gas block quickly mounted with hex screws and a new bolt carrier key, a couple springs and a bushing were all that was needed before adding the sleeved drive rod. Supplied front handguards mounted normally, and I was left going back over the installation manual, convinced that I must have missed something. It was that easy. Though it took me more than half an hour due to the troublesome factory gas block, this is certainly a task that can be accomplished by a moderately capable gun owner.

It is a well written review and worth reading.

This 3D animation shows how the piston system works verses the AR-15′s normal method of operation, direct gas impingement.

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18 Responses to “Adams Arms Piston Review”

Sort The Responses Below: Most Recent | Highest Rated
  1. Mikewrote on February 06th, 2012 at 4:51 pm Link To Comment | Reply To Comment

    The Adams kit shown here is GREAT! But it’s actualy more like the Mini 14 gas system than a true piston system, like the M14 or the new Ruger SR556. I have the Adams kit on an LRB upper. Works awesome. 0 problems and runs as clean as an AR can. Anyway the “piston” in this kit doesn’t move. It’s more or less a “pipe” that the gas goes through, then it expands in a small gas chamber that is part of the transfer rod which gets pushed back thus cycling the bolt. Just like on the Mini 14 gas system. There’s obviously a big difference in the way the parts between the two systems look, but the actual physics are the same. So the gas chamber moves, and the gas “piston” is stationary. The total oppisite of traditional (M14) piston systems where the piston moves inside of a stationary gas chamber and hits a transfer rod to cycle the bolt. I actually like the Adams kit more than a traditional piston system. It’s simple and easier to clean in my experience. That’s why I chose it. And I’m glad I did.

    Please rate this comment: Thumb up 0 Thumb down 0
  2. Pecasuswrote on September 11th, 2011 at 12:30 am Link To Comment | Reply To Comment

    I have a pistol length gas piston with the bolt on gas key,I installed exactly what adams arms instructed me to do.After 25 rounds the piston rod broke into two piece.Eventually the rod pushed the solid gas key up jamming my Bgc and got stuck,it was a pain to disassembled it.You need to buy their one piece carrier and stay away from the gas key bolt on.Other than that it was flawless!!

    Please rate this comment: Thumb up 0 Thumb down 0
  3. Robertwrote on November 03rd, 2010 at 6:55 am Link To Comment | Reply To Comment

    Dunhams in Pa stores have the new American Tactical AT-15 with the new Adams Piston system for $699 on sale normaly $799.

    Anyone know how dependable this system is or how it has been working?

    Please rate this comment: Thumb up 0 Thumb down 0
  4. skoalwrote on March 21st, 2010 at 12:10 pm Link To Comment | Reply To Comment

    I bought the Adams Arms piston Kit 2 weeks ago, and it just works! There is no carbon in the bolt or bolt carrier. Just use your common sense, where do you want all the junk, in the front or in action, that lets the job get done?
    I’m 58yrs. old been to nam and see what the di system does, just get over it, and try something new…..and this does work, I’m totally amazed.
    Common sense will tell anyone, if you are going to put the carbon back in the action, the action slows, just think about it, and you will see! And to all the guys and gals that want to use the di system go ahead, but Adams Arms system works, and that’ the long and short of it. If you don’t like it, don’t post, unless you have tried it, and I have and it works!!!

    Please rate this comment: Thumb up 3 Thumb down 0
  5. kershaw twrote on February 02nd, 2010 at 1:05 pm Link To Comment | Reply To Comment

    will the adams kit work on my M @ P ar15 ?

    Please rate this comment: Thumb up 0 Thumb down 0
    • zakresponded to kershaw t on February 02nd, 2012 at 5:16 pm Link To Comment | Reply To Comment

      Yea, Just take off the upper, attach the 5.45 upper to your S&W lower, and put in the 5.45 mag.

      Please rate this comment: Thumb up 0 Thumb down 0
  6. Adams Shortywrote on October 04th, 2009 at 8:20 pm Link To Comment | Reply To Comment

    I just installed the darbine length system with one piece bolt carrier about a month ago on a custom upper with a Daniel Defense 9.5 FSP Light rail. I have 2 other uppers one a 16 inch barrel with a AK 74 muzzel brake and the other a 20 inch with a rifle length gas system and both are Direct Impengment. After compairing all uppers the Adams Arms piston retrofit does make the rifle run cleaner and cooler where it counts, the bolt assembly! The recoil isn’t much different than a DI system but then the two DI uppers I have are Bull Barrels and one is compensated so they don’t move much. The AA Piston upper is lowder than the others due to a shorter barrel length and I’m using a FSC 556 Bulldog Brake from Addax Tactical (designed by Primary Weapons Systems) but all of that asside if feel like I’m shooting my Ruger 10/22!
    I don’t have much expierence with many other Piston uppers other than POF which is very well made as well so my recomendation is buy an Adams Arms kit.

    Please rate this comment: Thumb up 0 Thumb down 0
  7. Bobbywrote on August 06th, 2009 at 4:43 pm Link To Comment | Reply To Comment

    Why does everybody not want to clean their rifles?

    I want the piston system because it’s more reliable.

    That’s why I use the M6A3.

    Please rate this comment: Thumb up 0 Thumb down 0
  8. glwbearwrote on August 06th, 2009 at 2:20 pm Link To Comment | Reply To Comment

    I have a ADAMS ARMS Piston system in a AR Pistol and after some minor adjustments it is a super system to have!

    It makes the Gun so much eaiser to Clean and NO more carbon build up in the Bolt!

    I highly recommend it.

    glwbear
    34 years Law Enforcement & the Private Sector

    Please rate this comment: Thumb up 1 Thumb down 0
  9. splatacasterwrote on July 04th, 2009 at 3:44 pm Link To Comment | Reply To Comment

    How much would you have to shoot to notice a need for having either a long or a short stroke piston operating system??????
    Which is the best way to go long stroke or short stroke??

    Please rate this comment: Thumb up 0 Thumb down 0
  10. jdun1911wrote on June 16th, 2009 at 9:51 am Link To Comment | Reply To Comment

    Valhalla, AR15 piston does not make it cleaner nor more reliable. However, it does make it easy to clean.

    Please rate this comment: Thumb up 0 Thumb down 1
  11. jakewrote on June 15th, 2009 at 1:05 pm Link To Comment | Reply To Comment

    Why would you want to do this to a gun? like, what are the advantages?

    Please rate this comment: Thumb up 0 Thumb down 0
  12. Tomwrote on June 14th, 2009 at 12:00 pm Link To Comment | Reply To Comment

    @Dom: Except the Mini-14 doesn’t use a gas piston :)

    While the operating rod design of the Mini-14 is in some ways similar to a piston system, it’s actually got more in common with Remington gas-operated shotguns than true gas piston guns like the FAL or .30 Carbine. For anyone not familiar with the Mini-14 or piston systems, I’ll go into a bit more detail…

    Whereas a piston setup like the Carbine vents gas to push the piston into the op-rod assembly, the force of which pushes the rod backwards and operates the bolt, the Mini-14 has a gas aperture or valve which directly vents gas into a cavity on the op-rod. I guess you could say the Mini-14/Remington design eliminates the middle man, but it still cruds up the inside of your stock! The crud just isn’t in the working parts of the action, which is the big argument against direct impingement.

    Please rate this comment: Thumb up 0 Thumb down 0
  13. Carlwrote on June 14th, 2009 at 11:28 am Link To Comment | Reply To Comment

    While the piston looks better in theory, I understand there are some subtle advantages of the direct impingement system, like the recoil force being more on the center of the bore, and perhaps the barrel being subjected to bending forces from the piston. Or something else nobody has thought of…

    As always when upgrading or changing something, rigorous training and testing in the environment you intend to use your tool is prudent.

    Please rate this comment: Thumb up 0 Thumb down 0
  14. Domwrote on June 14th, 2009 at 11:27 am Link To Comment | Reply To Comment

    This is one of the reasons Mini-14 owners like Mini-14s. If only Bill had built an accurate gun, it would have been great. Adding this to your AR is very, very cool.

    Not sure about ROF but it definitely keeps the mechanism cleaner and thus more reliable. Blow-by definitely happens, Ken, I can tell you from experience with my Mini, but it doesn’t hurt anything.

    Please rate this comment: Thumb up 0 Thumb down 0
  15. Kenwrote on June 13th, 2009 at 3:47 pm Link To Comment | Reply To Comment

    Interesting…How do you prevent blowby on that “cone shaped” piston. Just a nerd question…lol!

    Please rate this comment: Thumb up 0 Thumb down 0
  16. Tomwrote on June 13th, 2009 at 3:52 am Link To Comment | Reply To Comment

    I’ve got three piston kits on my list of candidates for my next build, and Adams is up there. My only real worry is whether or not it’ll fit under Yankee Hill free float handguards, which I’m rather fond of. My current rifle has a “smooth carbine” handguard, so if the kits by CMMG or Adams will fit under that I’ll be saving up for one!

    Please rate this comment: Thumb up 0 Thumb down 0
  17. Valhallawrote on June 13th, 2009 at 3:10 am Link To Comment | Reply To Comment

    so, does this increase its maximum semi-automatic firing abilities, or just keep the gun cleaner?

    Please rate this comment: Thumb up 0 Thumb down 0
  1. skoalwrote on March 21st, 2010 at 12:10 pm Link To Comment | Reply To Comment

    I bought the Adams Arms piston Kit 2 weeks ago, and it just works! There is no carbon in the bolt or bolt carrier. Just use your common sense, where do you want all the junk, in the front or in action, that lets the job get done?
    I’m 58yrs. old been to nam and see what the di system does, just get over it, and try something new…..and this does work, I’m totally amazed.
    Common sense will tell anyone, if you are going to put the carbon back in the action, the action slows, just think about it, and you will see! And to all the guys and gals that want to use the di system go ahead, but Adams Arms system works, and that’ the long and short of it. If you don’t like it, don’t post, unless you have tried it, and I have and it works!!!

    Please rate this comment: Thumb up 3 Thumb down 0
  2. glwbearwrote on August 06th, 2009 at 2:20 pm Link To Comment | Reply To Comment

    I have a ADAMS ARMS Piston system in a AR Pistol and after some minor adjustments it is a super system to have!

    It makes the Gun so much eaiser to Clean and NO more carbon build up in the Bolt!

    I highly recommend it.

    glwbear
    34 years Law Enforcement & the Private Sector

    Please rate this comment: Thumb up 1 Thumb down 0
  3. kershaw twrote on February 02nd, 2010 at 1:05 pm Link To Comment | Reply To Comment

    will the adams kit work on my M @ P ar15 ?

    Please rate this comment: Thumb up 0 Thumb down 0
    • zakresponded to kershaw t on February 02nd, 2012 at 5:16 pm Link To Comment | Reply To Comment

      Yea, Just take off the upper, attach the 5.45 upper to your S&W lower, and put in the 5.45 mag.

      Please rate this comment: Thumb up 0 Thumb down 0
  4. Adams Shortywrote on October 04th, 2009 at 8:20 pm Link To Comment | Reply To Comment

    I just installed the darbine length system with one piece bolt carrier about a month ago on a custom upper with a Daniel Defense 9.5 FSP Light rail. I have 2 other uppers one a 16 inch barrel with a AK 74 muzzel brake and the other a 20 inch with a rifle length gas system and both are Direct Impengment. After compairing all uppers the Adams Arms piston retrofit does make the rifle run cleaner and cooler where it counts, the bolt assembly! The recoil isn’t much different than a DI system but then the two DI uppers I have are Bull Barrels and one is compensated so they don’t move much. The AA Piston upper is lowder than the others due to a shorter barrel length and I’m using a FSC 556 Bulldog Brake from Addax Tactical (designed by Primary Weapons Systems) but all of that asside if feel like I’m shooting my Ruger 10/22!
    I don’t have much expierence with many other Piston uppers other than POF which is very well made as well so my recomendation is buy an Adams Arms kit.

    Please rate this comment: Thumb up 0 Thumb down 0
  5. Bobbywrote on August 06th, 2009 at 4:43 pm Link To Comment | Reply To Comment

    Why does everybody not want to clean their rifles?

    I want the piston system because it’s more reliable.

    That’s why I use the M6A3.

    Please rate this comment: Thumb up 0 Thumb down 0
  6. Robertwrote on November 03rd, 2010 at 6:55 am Link To Comment | Reply To Comment

    Dunhams in Pa stores have the new American Tactical AT-15 with the new Adams Piston system for $699 on sale normaly $799.

    Anyone know how dependable this system is or how it has been working?

    Please rate this comment: Thumb up 0 Thumb down 0
  7. Mikewrote on February 06th, 2012 at 4:51 pm Link To Comment | Reply To Comment

    The Adams kit shown here is GREAT! But it’s actualy more like the Mini 14 gas system than a true piston system, like the M14 or the new Ruger SR556. I have the Adams kit on an LRB upper. Works awesome. 0 problems and runs as clean as an AR can. Anyway the “piston” in this kit doesn’t move. It’s more or less a “pipe” that the gas goes through, then it expands in a small gas chamber that is part of the transfer rod which gets pushed back thus cycling the bolt. Just like on the Mini 14 gas system. There’s obviously a big difference in the way the parts between the two systems look, but the actual physics are the same. So the gas chamber moves, and the gas “piston” is stationary. The total oppisite of traditional (M14) piston systems where the piston moves inside of a stationary gas chamber and hits a transfer rod to cycle the bolt. I actually like the Adams kit more than a traditional piston system. It’s simple and easier to clean in my experience. That’s why I chose it. And I’m glad I did.

    Please rate this comment: Thumb up 0 Thumb down 0
  8. Pecasuswrote on September 11th, 2011 at 12:30 am Link To Comment | Reply To Comment

    I have a pistol length gas piston with the bolt on gas key,I installed exactly what adams arms instructed me to do.After 25 rounds the piston rod broke into two piece.Eventually the rod pushed the solid gas key up jamming my Bgc and got stuck,it was a pain to disassembled it.You need to buy their one piece carrier and stay away from the gas key bolt on.Other than that it was flawless!!

    Please rate this comment: Thumb up 0 Thumb down 0
  9. splatacasterwrote on July 04th, 2009 at 3:44 pm Link To Comment | Reply To Comment

    How much would you have to shoot to notice a need for having either a long or a short stroke piston operating system??????
    Which is the best way to go long stroke or short stroke??

    Please rate this comment: Thumb up 0 Thumb down 0
  10. Domwrote on June 14th, 2009 at 11:27 am Link To Comment | Reply To Comment

    This is one of the reasons Mini-14 owners like Mini-14s. If only Bill had built an accurate gun, it would have been great. Adding this to your AR is very, very cool.

    Not sure about ROF but it definitely keeps the mechanism cleaner and thus more reliable. Blow-by definitely happens, Ken, I can tell you from experience with my Mini, but it doesn’t hurt anything.

    Please rate this comment: Thumb up 0 Thumb down 0
  11. Kenwrote on June 13th, 2009 at 3:47 pm Link To Comment | Reply To Comment

    Interesting…How do you prevent blowby on that “cone shaped” piston. Just a nerd question…lol!

    Please rate this comment: Thumb up 0 Thumb down 0
  12. Tomwrote on June 13th, 2009 at 3:52 am Link To Comment | Reply To Comment

    I’ve got three piston kits on my list of candidates for my next build, and Adams is up there. My only real worry is whether or not it’ll fit under Yankee Hill free float handguards, which I’m rather fond of. My current rifle has a “smooth carbine” handguard, so if the kits by CMMG or Adams will fit under that I’ll be saving up for one!

    Please rate this comment: Thumb up 0 Thumb down 0
  13. Carlwrote on June 14th, 2009 at 11:28 am Link To Comment | Reply To Comment

    While the piston looks better in theory, I understand there are some subtle advantages of the direct impingement system, like the recoil force being more on the center of the bore, and perhaps the barrel being subjected to bending forces from the piston. Or something else nobody has thought of…

    As always when upgrading or changing something, rigorous training and testing in the environment you intend to use your tool is prudent.

    Please rate this comment: Thumb up 0 Thumb down 0
  14. Tomwrote on June 14th, 2009 at 12:00 pm Link To Comment | Reply To Comment

    @Dom: Except the Mini-14 doesn’t use a gas piston :)

    While the operating rod design of the Mini-14 is in some ways similar to a piston system, it’s actually got more in common with Remington gas-operated shotguns than true gas piston guns like the FAL or .30 Carbine. For anyone not familiar with the Mini-14 or piston systems, I’ll go into a bit more detail…

    Whereas a piston setup like the Carbine vents gas to push the piston into the op-rod assembly, the force of which pushes the rod backwards and operates the bolt, the Mini-14 has a gas aperture or valve which directly vents gas into a cavity on the op-rod. I guess you could say the Mini-14/Remington design eliminates the middle man, but it still cruds up the inside of your stock! The crud just isn’t in the working parts of the action, which is the big argument against direct impingement.

    Please rate this comment: Thumb up 0 Thumb down 0
  15. Valhallawrote on June 13th, 2009 at 3:10 am Link To Comment | Reply To Comment

    so, does this increase its maximum semi-automatic firing abilities, or just keep the gun cleaner?

    Please rate this comment: Thumb up 0 Thumb down 0
  16. jakewrote on June 15th, 2009 at 1:05 pm Link To Comment | Reply To Comment

    Why would you want to do this to a gun? like, what are the advantages?

    Please rate this comment: Thumb up 0 Thumb down 0
  17. jdun1911wrote on June 16th, 2009 at 9:51 am Link To Comment | Reply To Comment

    Valhalla, AR15 piston does not make it cleaner nor more reliable. However, it does make it easy to clean.

    Please rate this comment: Thumb up 0 Thumb down 1

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