AR-15 Piston conversion question

04/05/14 | Self

[Blood of Tyrants]

I have been thinking of putting a piston conversion kit on my AR-15. What brand have you used and what is your experience?

[Blood of Tyrants]

Any Freepers out there who have converted their AR?

[MHGinTN]

I have done three: an Adams Arms, a CMMG, and a Osprey Defense. If you want the most versatile, use the Adams Arms since it can be turned off or turned down for reduced gas. It is also very easy to clean since the psiton and rod come out the front and then get cleaned and reinserted.

The most trouble free is the Osprey Defense, with a piston cup and rod which are darn near self cleaning with modern ammo. I'm into the second thousand rounds with the Osprey and yet to clean it or have any glitches.

The CMMG is a good system, allows easy conversion to .22lr ammo, and cleans up nice. But of the three I would go with the Adams Arms for ease of use, or the Osprey Defense for easiest conversion. I have the CMMG on an AR pistol with eleven inch barrel. It took a tiny bit of tweaking of the recoil spring to get it to run flawlessly.

All three of my conversions were on carbine length gas systems. I would recommend the Adams Arms for sure if you have a mid-length gas system ... most trouble free recoil action.

[Squantos]

I purchased a Sig piston gun and love it for 3 gun competition. Never converted one myself yet friends seem to be using Adams Arms uppers. Not sure of brand for “conversion” so will just bump this thread to the top for ya....

Stay safe !

[MHGinTN]

BTW, the OSprey uses your gas block. Just remove the retainer pin holding the gas tube and insert the Osprey tube with piston cup for the piston. With the other two you have to use their gas block because of the proprietary fitting of the piston rod and piston through the gas block. While not difficult to do, some folks have ‘mystery’ malfunctions, usually due to not getting the gas block perfectly aligned when changing out the gas blocks.

[Wingy]

I asked pretty much the same question a few months ago, and got hammered. And true, after much more research, I discovered that the advantages of a piston system were overblown and the disadvantages of a DI were also overblown. The best advice was to buy a complete upper already converted or convert yourself then you have both types to judge.

As to what brand to use, since I abandoned the idea, your own research awaits.

[Red Steel]

I discovered that the advantages of a piston system were overblown and the disadvantages of a DI were also overblown.

Agree.

[Noumenon]

FN FAL - piston by design

[Dead Corpse]

What are you using it for that you think a piston rig would work better than the original design?

[ChildOfThe60s]

Get an AK & an AR, then you can have what you want on any given day at the range.

My favorite is the one I happen to be using that day.

[JParris]

www.AR15.com

That is all.

[Thunder90]

This is probably going to be the best place to ask...

http://www.ar15.com/forums/f_3/126_AR_Piston_Systems.html

[lavaroise]

You will probably need a roller cam from POF because pistons tens tend to require more force to chamber imo.

[RC one]

I bought a stag model 8 a while back. Looking forward to shooting it this summer. I own several DI weapons too and used them exclusively in the service of course. They would get dirty. They would jam up from time to time. That's what we had S.P.O.R.T.S. for. Occasionally, that wouldn't even clear it. Cleaning that chamber out after a lengthy field training exercise was always a PIA. I think DI is not well suited for certain applications. For others situations, it works better than a piston or so we're told so it depends on what you want to do I guess.

All that being said, I have moved beyond the DI vs. gas piston dilemma to the PTR91 versus DSA FNFAL dilemma because after much deliberation on the matter I have come to the conclusion that DI versus Gas piston is irrelevant because, either way, the weapon is still chambered in 5.56 mm and 5.56 mm sucks as a combat round. There's just no getting around it.

[Patriot365]

I came back from putting about 400 rounds through my Sig 516. (piston) Went to clean it and it only needed a wipe down. Enjoy that DI system.

[Red Steel]

That’s fine. I may get a piston system sometime. I just agreed with wimpy. You may have problems shooting steel cased ammo out of it.

[Red Steel]

Right .308 is a better round than 5.56mm any day. But there are reasons that nations don’t field big battle rifles as their main issued rifles like FN FALs, M14s, G3s and alike ...like in their heydays.

[Red Steel]

Ooooh,

wimpy = Wingy ;^)

[RC one]

there are reasons that nations don’t field big battle rifles as their main issued rifles

Weight is more of an issue for such soldiers, especially when they're wearing body armor along with the rest of their gear. I am not so encumbered however.

[TurboZamboni]

Any experience with Huldra ? (IIRC, they’re made by Adams)

[MHGinTN]

No, not a minutes worth. I had thought of obtaining a Huldra 5.45 upper for one of my AR lowers, but the price was too high when I can build one myself. Now that 5.45 7N6 ammo is on hold by Fedzilla, the cost savings over 5.56 is no longer part of the calculus. Besides, I have a nice Bulgy in 5.45 now.

The 14.5 inch 5.56 with Osprey Defense piston kit is an amazing tool. I may pull it out and clean it now just for the fun of it ... I have over 1000 rounds through it without cleaning it. No glitches yet, since I tuned the recoil spring. The cost of ammo has put a severe restriction on my shooting. I am a member of a nice rod and gun club (Unaka Rod & Gun) but have built a small range in my garage because my shooting is now down to 9 x 18 and .22lr, and I'm getting low on .22lr!