.22 conversion for ar-15

[Circuits]

Edit: Whats the "ball detent" mod?

a hole drilled in the conversion bolt, and a notch milled in the .22 kit rail so that a spring-loaded ball bearing pops out of the hole into the notch when the bolt is fully forward.

Basically a new fix for bolt bounce in full auto or rapid semi fire, which can either supplement, or sometimes replace the full auto debounce weight when firing rapidly in semi, or in full auto. I don't have any pics, but a google search should turn some up on uzitalk or ar15.com in reasonably short order.

[Hoosier]

Thanks for this info, I've been planning on buying a .22 conversion kit for my AR.

[MrPrena]

I am seriously thinking about getting a CMMG 22 conversion kit as well.
I hear very good things about it.

Anyone who have/had bad experience w/ CMMG 22 conv kit?

[MichiganMilitia]

I've heard that 22.LR ammo fouls up your barrel and gas tube pretty bad... can anyone weigh in on this?

[Circuits]

If you're switching between .22 and .223 in the same upper, the recommended procedure is to fire a few rounds of .223 for every couple hundred rounds of .22 to blow the gas tube clean of any lead or carbon buildup, and let the jacketed rounds scour most of any lead deposits out of the rifling. Before I switched to a dedicated .22 upper (which has no gas port), I'd fire about five rounds for every brick/milk carton of .22.

Some buildup/blockage does occur, since it would often turn out that the first round or two of .223 wouldn't cycle the rifle at first after shooting a lot of .22. I'd single-load and fire each round of .223 with an empty magazine inserted, and consider it "blown clean" when the bolt locked back.

[MichiganMilitia]

Okay, so there's no known permanent damage or undue wear and tear on the 5.56/.223 upper?

[King]

I bought the cmmg .22 kit and had it out for the first time today. I shot 300 rounds of winchester wildcat. I had 3 FTF and 1 FTE. The kit doesnt like to extract unfired rounds so if you have a dud, it can be a pain to get it out. I am overall pleased with the kit. Its only .22 but it still puts a smile on my face. Definitely worth the investment imo. Only 3 FTF with cheap ammo didnt bother me.