Reviews & Ratings for CMMG 22LR Mk4 Barrel Kits w/ Bolt Group — 46 reviews — Page 1

I’m very impressed with this barrel bolt group kit. Very easy to install takes the guest work out of figuring out which BCG to pair with witch barrel. Put it together the day I got it took it to the range the following and have been having a blast with this little 22 plinker!

Top quality kit. No issues whatever. This was my first build of an Ar-15 upper and it went smoothly except for my learning curve. The barrel and bolt group were especially easy to work with. I highly recommend this kit for a 22LR conversion.

The fit and finish of this kit seems to be adequate for use in the CMMG upper receiver that I put it in, and it seems to be reliable after putting an AR15 buffer/spring in the buffer tube.

- The accuracy appears to be pretty terrible.
- I recommend it for training inside of 25 yards or inside of structures, but it does not appear to be useful for grouping at 50 yards.
- It reproduces (close enough) the weight and balance of a standard rifle. It does NOT reproduce the muzzle flip of a standard rifle (if that wasn't obvious).
- When using the reliable S&W M&P15 22 magazines along with a drop-in magazine adaptor from Redi-Mag, last round bolt hold open works properly, so this is a decent option for emulating the AR15 manual of arms while using 22LR ammo.

***BE AWARE***

Mine requires the use of something to keep the bolt carrier cage from sliding slightly rearward (out the rear of the upper receiver) during recoil. When this occurs, it prevents the bolt from reliably returning to battery. A standard AR15 buffer and action spring solved the problem 100% so far.

I bought one of these years ago and built it on the AR15 platform using a PSA upper and lower. One can buy a .22 look alike AR, but building it on the AR platform one cannot distinguish it from the real thing. I installed a teardrop forward assist which will not function as well as Magpul furniture, front sight base along with a carbine gas tube that of course will not work since it is blowback. A colt carry handle and side sling mount. I also added a 3.5lb 2 stage trigger. I prefer single stage triggers but I have a few 2 stage lying around. The gun works very well, including subsonic .22 through a borrowed suppressor. When I get around to it I will also build this one. Since the CMMG .22 has the A4 profile barrel I will keep it that way and add a pinned front sight base instead of a free float handguard. The barrel is 16.1" but it goes further into the upper than a 5.56 barrel so it does not stick out past the sight base as far as a 16" 5.56 legal carbine barrel does. The barrel it threaded 1/2-28 so any muzzle device will work. I have an A2 birdcage on mine, not tightened of course. CMMG recommends a certain trigger, but the aftermarket 3.5 LB one I put in it works good.

Dropped this in my AR15/22 Dedicated build. Fired over 600 rounds flawlessly so far. Cheap ammo. Fun for my entire family. My wife loves it. Highly recommended this for anyone looking to build a dedicated 22.

What's better than 22lr? What's better than an ar? Being able to shoot one affordably. Right now there's no ammo. This fixed that problem. So smooth. Even smoother than a standard ar22. Superb. Lightweight.

I bought CMMG 22lr for a dedicated ar22 build. Not finished with the build, but this is definitely a quality product. Heavy, and built well. Everything seems to be good to go with the bcg and barrel combo.

I did a little customization to my setup so I could run the Smith and Wesson M&P 15-22 mags. I had to use the Boonie Packer Better Mag adapter to get the M&P mags to fit and cycle properly but now it runs great and the bolt catch/release functions properly and it will hold the bolt back after the last round. It feeds and fires whatever ammo I put in it, will rapid fire with no issues and is pretty accurate. I built this dedicated 22LR-AR with identical parts my 5.56 AR so I could practice on the same platform with cheaper ammo and now it gets used a lot more than my 5.56.

I did a dedicated build, rather than converting .223/5.56. Built the AR15 with everything as milspec, then dropped this in with my CMMG mags and it runs flawlessly. Rings steel at 100yds all day every day.

I used one of these kits to build a dedicated .22LR upper for my lower with binary trigger. Does not disappoint! I can empty a 50 round drum in seconds. Not only does it keep up with my binary trigger (and likely full auto as well) it is very accurate. Biggest downside? It has pretty much retired my Ruger 10/22.