CMMG AR-15 .22 LR Conversion Kit review

Ceiner has been producing AR 22 Conversion kits for many years. Some of them worked well and some of them didn’t. If you were lucky enough to get one that worked well then you were laughing all the way to the shooting range. If you didn’t get a good one it was a nightmare working with Mr Ceiner to get it fixed or replaced. The best resolution was to start over and buy a new one hoping you had better luck next time around.

After having owned a Ceiner kit I was a little sceptical about the new CMMG AR-15 .22 Conversion Kit. I bought 3 of them just to test for quality control and function. I bought 2 carbon steel and 1 Stainless kit as well as a whole pile of magazines. I couldn’t be happier. CMMG is committed to their customers and their products. The quality control is excellent as all 3 kits have worked flawlessly. Maybe it’s the AR’s I have, but my kits love the Federal bulk pack ammunition you can buy at Wal-Mart. If you want total reliability buy the Federal 325 round Semi Auto Match packs. I haven’t bothered to test much else because the Federal stuff works so well.

Top: Standard Mil-Spec AR-15 Bolt Carrier & Bolt. Center: CMMG Stainless .22 Conversion bolt. Bottom: CMMG Carbon steel .22 Conversion bolt. Also show is a .223 fired case.

For those unfamiliar with what the conversion kit does, read on.  The conversion kit replaces the bolt in your AR-15 rifle or carbine. The replacement bolt has a .223/556 steel case attached to the end of it that goes inside the chamber of your barrel. The steel case has a .22 LR chamber inside of it. The kit uses your barrel and is quite accurate as there is only a couple of thousandths difference between the diameter of .223 and a .22LR. The kit doesn’t utilize the gas system on the AR.

The conversion only takes a minute to install or remove. Pop the back pin on your AR. Pull out the charging handle and bolt. Put the charging handle back in and replace bolt with CMMG .22 Conversion bolt. Put upper and lower back together. You’re ready to shoot.

The bolt stays open on the last shot. The kits are easy to take apart to clean. I have been extremely impressed with the reliability and accuracy. I’m also told that CMMG test fires every kit before packaging. In my testing the stainless kit isn’t any more reliable than the carbon steel kits. The stainless does clean a little easier.

The magazines work great and are the same size as standard AR-15 Magazines. The CMMG 26 rounder is the same size as standard 30 rounder and the 10 and 15 round magazines are the same size as a GI 20 rounder. I’ve had people at the range tell me I needed to buy aftermarket magazines but I haven’t seen the point yet as the CMMG mags work great.

Keep the kits clean and oiled and you’ll be amazed at the reliability. I’m approaching 4000 rounds through my two kits and they still look like brand new. You’ll also be shocked at how much money you can save in ammunition costs. The other huge benefit is that you can practice with the same gun, trigger, optics, irons, controls, stock, etc that you use for self defense, duty, plinking, competition, or hunting.

.22 LR Cost Per Round .223 Cost Per Round
$0.033 $       0.40
Cost Per 1000 Rounds Cost per 1000 Rounds
$    33.00 $  400.00
It costs the same to shoot 12 .22LR as it does one 55g .223 round
The CMMG .22 Conversion Kit can broken down easily for cleaning with no tools in seconds.