Sunday GunDay: .22 LR Conversion Kit for AR-15 Platform

Over the past 18 months, popular ammo types, such as .223 Rem and 9mm, have been hard to find at reasonable prices. The high cost of .223 Rem centerfire ammo has driven more folks to shooting .22 LR rimfire ammo, both for fun and practice. This Sunday we look at a smart solution that allows you to shoot .22 LR ammo from your existing .223/5.56 AR-15 platform rifle. This is great because it allows low-cost training with no change in rifle balance, ergonomics, and/or optics.

The CMMG Bravo .22 LR Conversion Kit provides a replacement bolt/bolt carrier along with three 25-round magazines with special .22 LR-fitted followers and ammo slots. This allows you to shoot rimfire ammo from any AR-15 chambered for the .223 Rem (5.56×45). The CMMG Bravo has an integrated extension that fits into your current chamber. The rimfire bullet passes through this extension and then enters the barrel.

The CMMG Bravo conversion Kit comes with blowback-operated .22 LR bolt carrier, rubber protector for bolt carrier tip, and three 25-round polymer magazines. To use, simply replace the rifle’s .223 Rem bolt and carrier with the Bravo .22 LR conversion unit and load up the included magazine(s) with rimfire ammo.

To use the CMMG Kit, simply remove the centerfire bolt/bolt carrier, and replace it with the CMMG silver colored bolt shown above. CMMG states: “For best performance use a round-style hammer as notched hammers can cause function issues.” Testers have stated that high-velocity .22 LR ammo works best, and CMMG notes that “36gr plated-nose bullets have proven to be the best choice for function.” The copper-plated bullets help reduce fouling.

Ultimate Reloader Tests CMMG .22 LR Conversion Kit

Our friend Gavin Gear of UltimateReloader.com recently tested the CMMG .22 LR AR Conversion Kit. He observed that installation was very straight-forward and the CMMG magazines worked well. He and fellow tester Travis Fox shot the unit both slow-fire and rapid-fire successfully.

Gavin and Travis found the CMMG Kit easy to install and fun to use. With an AR that can shoot both .223 Rem and .22 LR, it’s like having “two guns in one”. Travis was impressed with the ease of use: “It is so simple to change over to the CMMG .22 LR AR kit! It took me about 68 seconds the very first time I tried. Each time after that it took me about 40 seconds — it’s that simple. It takes longer to fully load one of the mags than it does to switch over from .223/5.56 to .22 LR and back.”

The AR shot very well with the higher-velocity ammo types. 100% functioning was achieved with both 40gr Federal Game Shok ammo and American Eagle High Velocity 38gr Copper-plated HP ammo. NOTE: CMMG does recommend high-velocity Copper-plated rimfire ammunition.

Maintenance Tip — After converting back to your centerfire .223 Rem (5.56), Travis says “make sure to clean the gas tube and components as .22 LR tends to run dirty”. READ Full Test on UltimateReloader.com.

CMMG Bravo Conversion Kit Gets Thumbs Up from Gavin and Travis
“Does this conversion kit get the Ultimate Reloader stamp of approval? Absolutely! In these times of ammunition/component scarcity this gives options to shooters. Finding bulk .22 LR can sometimes be easier than 223/5.56. This kit gives that option at a great price. Any chance to keep skills up and familiarize new shooters to a platform is a good thing. Basically two rifles for a lot less than another rifle.”

How to Install CMMG Bravo .22 LR Conversion Kit

The Brownells video below shows the installation process step-by-step:

In this instructional video, a Brownells gunsmith demonstrates (step by step) how to install, disassemble, clean, lubricate, and reassemble the CMMG AR-15 .22 LR Conversion Kits. Clear the rifle and make safe before you start the conversion. Separate the upper and lower, remove the standard bolt carrier group. You then install the conversion bolt and connect the upper and lower as normal.

Details of CMMG .22 LR Conversion Kit

“For years I’ve had a CMMG conversion kit. It’s a drop-in system that’s … very reliable and it’s accurate. The [CMMG conversion] has lower recoil [and is] great for training. Even though ammo prices have gone through the roof, .22 LR is still cheaper to shoot than anything else.” — SootchGear

This SootchGear video shows how to install the CMMG Bravo unit. The video also compares the original CMMG .22 LR bolt assembly with the latest integrated CMMG Bravo at 2:00-3:50. The older unit had a brass adapter and separate chamber insert. The host also tests a CMMG-equipped AR with various types of ammo. Watch a rapid-fire sequence starting at 1:48 time-mark.

Field Test with Two ARs — Rapid Fire .22 LR Testing

The video below demonstrates rapid-fire .22 LR performance with two different ARs using CCI Mini-Mag ammo. The CMMG conversion is fast and easy: “In a matter of seconds you go from 5.56 to .22 LR”. Watch rapid-fire at 5:40 with CCI Mini-Mags in red/black rifle. Then the tester shoots a variety of ammo in a .223 Wylde-chambered all-black AR, starting at 9:40. The Mini-Mags worked flawlessly, but there were a couple fail-to-cycle sequences in extreme rapid-fire with cheaper “bulk” ammo. The lesson here is use good quality, high-velocity ammo.

NOTE: This 2018 video shows an earlier CMMG .22 LR conversion bolt that features a brass adapter and separate chamber insert. The current CMMG Kit has unitized bolt without a separate adapter or insert.

Interestingly, the Mini-Mag .22 LR ammo shot fine in the .223 Wylde-chambered AR. However, CMMG cautions: “Since .223 WYLDE is NOT a mil-spec chamber, we cannot guarantee fit or function with our 22LR conversion kits.”

Reviews from CMMG Bravo .22 LR Rimfire Conversion Kit Purchasers:

“Get it. Bought this for my Rock River AR. Bolt system goes in [easily] and fits perfectly. Took it to the range and put over 150 rounds through, only failing to feed/fire two rounds. I most definitely recommend this product to anyone looking to shoot their standard AR-15 .223 rifle on a budget.” — Pew P.

“I got this just yesterday and in two days time I have put a couple thousand rounds through it and no hick-ups. I have no complaints.” — Seth

“Best buy for anyone during this ammo crisis. Ammo is extremely expensive and hard to find. It was a ‘no-brainer’ once I found this kit. Ran 200 rounds to break it in for about $20 and had maybe 3 failures. Accurate up to 50 yards (I haven’t tried further) without optic adjustments.” — Joshua M.

“Purchased one of these in January. Took it to the range shortly after for my daughters to try out. We have three ARs and this thing functioned flawlessly. We practiced swapping out the 5.56 carrier with this back and forth, flawless. Enjoyed it so much now I’m purchasing another one.” — J.B.

“Great product. I bought this due to the high cost of ammo. I wanted to still shoot my AR and this was an alternative. This thing works great… works flawless with different types of .22 LR, from premium CCI to the cheap stuff. I recommend this to anyone thinking about getting one.” — Thom

* You can get also CMMG Conversion Kits from Brownells with one (1) 25rd mag for $219.99, or with three (3) 25rd mags for $249.99. There is also a CMMG kit with three (3) 10-rd mags for $249.99 for areas with capacity restriction.