I’ve been toying with the idea of picking up a dedicated .22LR AR to practice with because my club doesn’t allow high power rifles to be used in the action bays and there are only opportunities to shoot Practical Rifle once or twice a month without traveling elsewhere. There is also a significant savings to be realized by training with .22LR over the 5.56 that typically goes down the barrel of my AR so that was also a big motivator for the new rifle. But there were two problems with adding a dedicated .22LR AR to the collection, one being the cost. Not only is a reliable .22LR AR on the spendier side for a semi-auto rimfire rifle, but it would require the addition of an optic as well. The other problem is that none of the .22LR AR rifles I held were a close analog to my actual AR(s) so they probably weren’t going to be as good as a training platform as they could be.

After a little Google’ing I ran across a few different options for a training AR like dedicated uppers and massive conversion systems that were pretty evasive on my current rifles. Not wanting to disturb my current systems I kept looking and ran found the .22LR conversion kit from CMMG. This system consists of a conversion kit that you simply swap out your AR’s complete bolt carrier group for this chunk of stainless steel and dedicated .22LR magazines that have the same form factor of a normal AR magazine. That’s it. That’s all you do. Pop the rear take down pin, pull out the BCG and slide in the kit and you’re ready to lay waste to your bulk packs of .22LR ammo.

Being a very skeptical person I expected this thing to be too good to be true. I envisioned some ill fitting, chamber damaging, stove pipping device that would infuriate me and have me in line at UPS shipping it back with a nastygram, but I am happy to report none of those things happened. In fact, I am shocked at just how well this thing works!

My friend and I grabbed an open bay and setup several IPSC targets then inserted the CMMG kit into my RRA. It took some effort filling the new mags with the 26 rounds required to fill them up but after some time and numb thumbs we were ready to go. I inserted a mag, charged it and let it rip! And rip it did. The instructions indicated that it would probably malfunction a bit as part of the break-in process but it dutifully ingested everything we gave it. Being curious about whether or not it would eat cheap ammo I brought out a variety of .22LR ammunition to see what brands it would eat and what brands it wouldn’t. I’m happy to report that it devoured anything I loaded into it, even the Remington Sub Sonics that nothing I have will cycle! Even under rapid fire the kit performed flawlessly and cycled through 300 rounds without incident.

This particular AR’s barrel is a 1:9 twist which is nowhere near optimal for a little 36 grain .22LR bullet, but it did surprisingly well at the range we tested it out, which was around 25 yards. Handheld groups through the EOTech would easily remain in the head portion of a standard IPSC target. It did however print a few inches lower than my dot so I have to give the elevation knob a twist when I use the kit.

Other things worth mentioning. It is dirty. Damn dirty. After testing it I hit the benches and as recommended put some .223/5.56 rounds through it to “blow it out”. I was surprised at just how much smoke bellowed out of my rifle not only the first shot, but the first five shots. After some experimenting with various types of ammo it seems like copper plated rounds are substantially cleaner than their non-plated counterparts. One other noteworthy observation is that although the kit had no problem whatsoever cycling any type of round I put in it, the magazine seem to bind up with anything over 36 grain bullets. I’ve settled on Federal Bulk packs of ammo for this application.

One last note on CMMG as a company. When the kit arrived it had a crack in the very end of the chamber sleeve, but after a quick call to CMMG I had a sincere apology and a replacement in a couple of days. Not hassle and no BS. Kudos to them.

So if you’re looking for a great way to practice fundamentals, target transitions, getting in and out of positions, pretty much anything but recoil control, pick up one of these kits and save some money/train longer.


If you would like to see this kit in action, see my First Speed Steel Match video where I use this kit.

Review Of CMMG’s .22 Conversion Kit