AR Piston Conv. Kits-which one?

[Rokman]

I am interested in purchasing am Adams Arms, CMMG, etc. piston kit for a mid-lenth upper that I have and am hoping to get feedback on likes and dislikes of users of these kits. I am not interested in discussing the differences of direct impingement and gas piston systems since I understand that. I just want to know if you like your kit and would do it again.

 

[The_Hammer_Man]

I've installed both on customer weapons and while the CMMG gives you alot for your money the Adams Arms kit is a little better engineering wise as well as machining/finish.

Objectively there is very little difference between the two units.. subjectively... they feel different. Hard to describe it.. the CMMG feels "mushier". (This is the general description given by people who've tried them side by side.

All boils down to what can you afford.

 

[Rokman]

Thanks Hammer Man. The sources that I have found, have them for about the same price. I am leaning towards the Adams Arms. I know sombody else has at least tried one of these piston kits. I could not glean enough good info from the searches to satisfy my curiosity. Please let me know.

 

[Double Naught Spy]

Which one do you think will be making the exact same parts for the kit in 5 years? Piston kits seem to be in their infancy and have undergone some changes. You might consider holding off until you are certain that what you are buying will be around for a while for when you need replacement parts.

 

[Rokman]

Holding out for awhile to see what happens is probably a good idea, since I am not in a hurry. Just looking to try something else.

 

[trigga]

don't know if it's true but i've heard somewhere that the piston system is not as accurate as the d.i. system in ar platforms.

 

[Extremely Pro Gun]

That is true. It adds lots of weight, decreases interchangeability of parts, adds no more firepower. All in the name of moving the dirt up to the front of the rifle.

I would go with the Adams Arms, but I would not do it unless I was going to war in the sand. I would also want to be able to change it back easily.

 

[trigga]

instead of just the bolt moving into the buffer, the piston is also moving. longer movement = less stability.

 

[The_Hammer_Man]

I can see how you might think that Trigga.. but the converse seems to be the case.

All the owner of the rifles I've added this type of system to have reported INCREASED accuracy. Their opinions on this, as well as pretty extensive testing by yours truly, seem to be with the change in recoil characteristics. It often does soften subjective recoil.

The thing to remember is that with piston drives you achieve kind of a "pushme-pullya" energy transfer.

Explanation: When the bullet travels down barrel the piston , after the bullet passes the gas hole, travels to the rear of the weapon. This tends to balance the forces engendered. What that means in real world terms is that it shortens the time needed to get back on target by limiting muzzle rise. Now granted a good muzzle brake will do that too but, this type of system does it while the bullet is still in the barrel. Not after it's left it.

This characteristic is one of the reasons piston drives have become so popular with 3-gunners.

 

[Double Naught Spy]

All the owner of the rifles I've added this type of system to have reported INCREASED accuracy.

That very interesting. Based CY6's AR15/M16 Armorer's course instruction by Sully Sullivan, that has NOT been the case. Reduced accuracy was noted by the two students in the class with them as well, though the loss of accuracy was minor, along the lines of a half MOA.

 

[Rokman]

Guys, you are missing the point. I have several DI ARs and was going to convert one of them. I have read all about the differences between the two by doing a search and am not worried about that. I just wanted to know from users of the various kits, what they liked and did not like. Are they durable, or are they junk. Do they work, do they fail. I think that I will stay with DI and save my money for now.

 

[The_Hammer_Man]

In descending order of my personal preference in gas piston retro fit kits.

Osprey Defense : easy to install and mine has 3k round through it w/ no problems.

Bushmaster: Again easy to install. gas tube retro kit like the osprey. Might be more robust.

CMMG: Good kit but I don't really care for the "feel" of it as much as I do others.

Adams Arms: My personal favorite for retro kits with adjustable gasblocks. Robust as hell.. haven't had it malf on me once.

 

[HOLY DIVER]

i've got a friend that shoots allot of 3-gun he fitted his race gun with a cmmg piston kit and had allot of issues with it infact he removed the kit because he could not get it to run,osprey or adams i've not talked to anyonein person thats running one of there kits

 

[Rokman]

That's good info guys. Thanks

 

[The_Hammer_Man]

For shear out and out reliability I'd have to put the Osprey Defense retro fit kit at the top of my personal list.

For reliability and functionality, ie, adjustability,out of the box, I'd go with the Adams Arms.

The reason I like the Osprey better for retro fits is because you don't have to disassemble the barrel group in order to install it.

All you do is pull your forearm covers and uninstall the gas tube. Install the piston expansion chamber and the upper reciever bushing into the inside of the gas tube hole and you're pretty well done. Install two more parts and this weird looking little spring retainer they give ya and you're done.

Here's a link to their install video:
http://gaspiston.com/video/osprey-defense-5-minute-installation-video/