CMMG AR-15 Piston Conversion Kit- Review

you get over it fool.. i care less bout you crud setup??

I have a piston kit by areas defense. I installed it years ago when AR15 piston kits 1st came on the scene.

And what not & all that jazz

You put 1800 rounds through that weapon without cleaning? Have you lost your frippin' mind? NO soldier in my platoon hit the rack after patrol without removing bolt carrier and bolt from their weapon and cleaning it, whether firing it or not. And then every three days they broke their weapon down completely to parade rest and gave it a THOROUGH cleaning with a "white glove" inspection by their team/squad leader.

There's a video on how the military "can't fix the di system" in the m4/16 series. So I offered my .02 on my cmmg conversion and it's success. Well some guy just had to argue "converting will tear itself apart!!!" Thank you for confirming I'm not making shit up lol

I have a cmmg mid length. I got it probably got it in 2010. Got mine as a complete upper. Runs like a top. Cmmg quit making them. They offered to convert mine to di for free. I guess they just don’t sell them as much as they used to.

Love to see an Osprey Piston Kit video or An Adams Arms!

I'm saying this because your reviews are very comprehensive compared to other tubers. Plus it would be cool to see which one you like most.

Looking forward to the possibility of that happening.

damnit man how do you get those dust covers on the bottom of the mags, no matter how hard i try they wont seat all the way on like yours. great vids keep em up c:

Adams Arms makes something similar I wonder if it holds up as well as this AR.

Liked the video.
Do you have any videos of the AR57 conversion or any experience with them ?

Just picked up a Barrett Rec7 Gen2 and it is very light comparable to my bcm, was not disappointed. It was accurate, reliable with 300 rounds through so far, and stayed clean. Cant decide between piston and di just buy both lol

Damn shame they stopped making them!? ;(

Hey ARG, what do you think of Adams Arms rifles?

I'd be curious to see if the bcg from an Adams arms kit would work in a pinch in this one. From what I can tell though the op rod looks like it comes back a tad farther on this one.

you have any experience with the Adams Arms piston kit? from what I've read that's one of the higher quality kits out there and doesn't add a whole pound and a half to the rifle

Nice piece of kit but for that price I'd buy a complete Adams Arms upper. $550 for a base upper and sometimes as low as $450 if you catch a sale.

Great review, I still think AR's built from the ground up as Piston rifles are a better option if you don't own an AR but this kit ain't bad at all for $400 with a bolt carrier. I really like the spring loaded bolt. I removed the gas key rings from my SIG516 so it could cycle with less friction but the draw back is that you can hear it sloshing around sometimes. I like the fact that it has a one piece bolt carrier. IMO I think all AR's bolt carriers; piston or not should be one piece. Good review 👍.

with a di gun, the gas pushes the carrier rearwards, but at the same time pushes the bolt toward keeping it locked. The spring is probably just to keep the bolt locked a little longer while the carrier starts to move rearwards, just like in a di gun. It can't be THAT necessary cause the lwrc I had didn't use the spring and functioned flawlessly, piston ar's just ain't my cup of tea.

What rail system?

Excellent video and excellent timing for me.Thank you for your opinions as I do trust them when it is something new to me.

Good stuff!

Nice.  I never shot an AR piston.  My buddy jus got an AA piston upper, we shall see.

Dude you train a lot. That is awesome. Keep it up.

I think the bolt spring is for timing. To keep it from unlocking early.

What sight do you use ?

What ammo do you use and what do you pay for that in the USA ?

10:52 the carrier look's cracked?

…these are great!

Dude, just checked around, MidwayUSA and Brownells both list these as discontinued.  And Sportsmans Guide.  Brownells has 9 left on sale.  CMMG's website doesn't seem to have a listing for them.  I think they've decided to cede the conversion market to Adams Arms.

does the piston make it as reliable as an ak

Awesome video. Glad you made this.

I don't really care for the gas piston kits. People act like "man stoner fucked up when he designed this…everyone know s you need a gas piston"

truth is, gas pistons aren't anything new, they been around as long as semi-autos themselves….Eugene Stoner was doing something a bit revolutionary and out of the box when he designed the AR with a a DI system and it does have its advantages. 

so my thoughts are….if you absolutely insist on a gas piston….then just get a damn AK…or maybe another 5.56 rifle that was designed with a gas piston.

seems like a must to buy/…

Good info bro

Great content and input.

Excellent review of the kit. Thank you for taking the time, ammunition, training (VR) and effort into this and giving free information. Much appreciated.

I have always been in the mindset of ar or ak… no frankenshit