CMMG Drop-In .22LR AR-15 Conversion Kit



The CMMG .22LR drop-in AR conversion kit has been around for some time.  They are not a new product by any means, but I have never used one and most of the reviews I found of them were several years old.  I have been wanting to either get a dedicated .22LR AR or one of these kits for a while.  I figured either would be a great way to introduce my wife and kids to AR shooting without the very loud report of the .223 that might otherwise scare them off.  I had been keeping my eyes open for one or the other when I stumbled upon this kit at a recent gun show I attended.  The price was right (far less than half of the price of a dedicated .22LR AR) so I grabbed it.
CMMG kit pictured adjacent the standard .223 bolt carrier group and magazine
The CMMG kit I purchased is labeled as their “Bravo Model”, at least according to the packaging.  It is constructed of stainless steel, with the exception of a brass bushing that fits into the locking lug area of the barrel extension.  The front end of the CMMG kit replicates the shape of a .223/5.56 cartridge casing and functions as a short section of barrel before the round reaches the actual barrel.  The kit functions on straight blowback operation and is completely self-contained.   The spring and buffer in your AR get some time to rest when using this kit as the small spring visible at the rear of the device is the actual recoil spring.  The device appears solid and well-constructed.  Mine came with one 25 round magazine that also appears solidly made.
VIDEO


In one of the reviews I had read, there was mention of having to file down some small blocks on the magazine to get it to fit properly in the magwell, but I experienced no such issues.  The magazine fit perfectly in the magwell of my Stag lower right out of the packaging.
Minimal shift in point of impact between .223 and .22LR
This morning I was able to get out and do some testing.  I was going to be testing this in an AR that I built.  It is a conglomeration of parts (Stag lower; DPMS upper, bolt and carrier; DPMS lower parts kit; BCM 16” mid-length gas system, 1-8 stainless barrel; BCM Gunfighter charging handle; topped with an ultra-affordable Bushnell TR-25S red dot optic) that I slapped together, but has functioned perfectly since the day I built it.  The only problems I have ever experienced with it were a few failures to feed with Wolf hollow point .223 ammo (purchased hollow point accidentally one time).  I was anxious to see how well this kit would function, but I also was interested to see how much of a shift in point of impact I would experience between both calibers, as none of the previous reviews of the kit, at least any that I had read, did any back to back comparisons.
I hung some clean paper and set myself up at about 45-50 yards.  I fired two rounds of .223 to check and see where I was printing.  Next, I installed the kit and fired five rounds of .22LR.  I was pleasantly surprised by the results.  There was a shift, but nothing drastic.  All of the .22LR rounds struck within two and a half inches of the .223 impacts.  If I were a sniper or planned on taking head shots, this would concern me, but since my plans for this kits consist of just putting rounds on paper and steel, this minimal shift is more than acceptable.
Once I had noted the change in point of impact, I decided to run it hard to see if I could induce any problems.  I went through magazine after magazine (stopping to reload after each since I only have 1 magazine at this point) without a single hiccup.  As fast as I could pull the trigger, this little thing kept up, and the smile on my face got bigger and bigger.  I really enjoy shooting my AR’s, but lately the cost of ammo has interfered with that.  Thankfully, I have quite a stockpile of .22LR and now I have another gun to help me burn through some of that.
Converting from .223 to .22LR takes only a few seconds.  There are no permanent modifications required of the rifle, and all of the controls work as they should with only one exception, the factory bolt-catch does not work with the kit, but it also does not interfere with it.  The video below shows me firing it both calibers and converting in between so you can see how quick and easy it is.  While it functioned perfectly in my home built Frankenstein DI rifle, I am curious to see how well it will work in my piston operated LWRC.  I will be bringing that home from work this weekend (my weekend which is most people’s work week) and will add an update to let you know if there are any compatibility issues with it.
Overall, this CMMG kit is a great value.  It costs hundreds less than a dedicated .22LR AR, allows you to train with your rifle for pennies on the dollar where ammo is concerned, point of impact shift is negligible, it is well made and has been 100% reliable thus far.  If you have been debating on which way to go (drop-in or dedicated .22), or have been wondering if these CMMG kits are worth what they charge, I would have to reply with an unequivocal yes.