CMMG AR-15 .22 L.R. Conversion Kit

[billt]

I finally picked up a CMMG AR-15 Conversion Kit from Primary Arms the other day. They had them on sale for $170.00 + tax & shipping. I've heard good reviews about them, as far as accuracy and functioning, so I figured why not? I have several AR's, and this kit makes them all the more useful. I have a ton of .22 ammo I've collected over the years, so ammo wasn't a concern. Do any of you guys have them, and what kind of results have you gotten with them, accuracy and functioning wise?

I bought the "Bravo" Model that comes with 3, 25 round magazines. I didn't care for the blister pack it came in, so I went to Harbor Freight and picked up one of those Apache Pelican style cases with the "pluckable" foam rubber inserts to store it in. For only $30.00 you can't beat it. Anyway, just as soon as it starts cooling off here, I'll light it up and test it with a bunch of different ammo. A 1 in 7" twist really over rotates the bullet at a factor of over 2 to 1. But I've heard that accuracy isn't too bad in spite of this. We'll see.

 

[EddieE]

Curious how it works. Just checked their site, I have been wanting a conversion upper. They are pricey!

 

[BKSSNIPER]

We used them as trainers at my old department some. They run pretty good, they like to be clean and wet. As far as accuracy we never really tested them but they shot around an 1” at 20 yards or so.

 

[KML7201]

I have 2 CMMG 22 BCGs and dedicated 22LR barrels. They both run great using standard velocity 22.

 

[6.5SH]

I can't suggest this little kit highly enough:

22lr AR Reliability Kit

Patented The Standard Reliability Kit includes: 1x Pressure Plug, 1x Charging Handle Insert, 2x Firing Pin Spring, 2x Power Extractor Spring (one of each force level), 1x Bolt Buffer (extras are av…

borebuddy.com

The pressure plug and the charging handle insert are the two mandatory items IMO, springs are always handy to have.
If using hyper-velocity ammo their weight kit is worth looking at.

If going the other way with really low velocity ammo you may need to look at lower weight hammer spring as there may not be enough energy to fully cock the hammer. These work well:

AR15 Mil-Spec Reduced Power Spring Set | AR10 Mil-Spec Reduced Power Spring Set

This spring set is designed for a reduced pull weight when used in AR15 & AR10 Rifles. It replaces the factory springs found in a common GI Mils-spec LPK. The reduced weight lightens the trigger pull of stock GI triggers both in single stage and double

www.taylor-tactical-supply.com

I use mine for PCC type informal matches. Hitting the breech and bolt faces with a toothbrush before you come off the line seems to help keep it ticking.

I'll also second what BKSSNIPER said, they like to be wetter a than typical .22 does.

 

[flyfisher117]

I had one of these. It was in an old 1:9 twist barrel. Accuracy on mine was horrible, minute of pie plate at 50 yards with mini mags.

Also definitely clean the bore and gas tube if you go to switch it back to centerfire.

My buddy did a dedicated CMMG build with the proper barrel and bolt assembly and it was much better. I eventually sold mine.

 

[erik72]

Firing .22LR from your AR using the CMMG conversion bolt is a hoot. I suspect you'll enjoy it so much you'll want to build a dedicated upper for it. A dedicated barrel (and collar) will give you better accuracy. 22LR is pretty dirty so copious amounts of oil will only gum up the works quicker. Lubricate but use lube sparingly or try a dry lube. I'd still clean every 200 rounds our so for best function. I never fired much through a .223/5.56 barrel so I can't speak to clogging up the gas tube. Just something to keep an eye on for safety's sake though.