Choosing an AR-15 .22LR conversion

[socalbeachbum]

help me choose a .22LR setup for my AR-15. I had a CMMG conversion kit, and initially it fed and was reliable in a Stag Arms AR, then once I switched to a new M&P-15 I had reliability problems feeding issues.

CMMG sent me another, reminded me to get a 1 in 16 dedicated upper if I wanted accuracy. I still had feeding issues, so I sold the kit. But I never kept track of what ammo I was using. I know I tried different brands, with no real difference.

Could there have been anything about my Stag Arms AR that made it better than the M&P?

I'm ready to buy a dedicated .22LR upper now, what should I choose for barrel, bolt group and magazine?

 

[holdencm9]

If you had feeding issues with one AR, and not with another, it probably had more to do with the lower than the upper. Because the conversion bolt is entirely self-contained. It does not move within the upper (or at least, it shouldn't). There could have just been a tiny bit of difference in how the lower receiver mag well was shaped, that it fed the rounds at a slightly different angle, that the conversion kit did not like. If you have enough play in the mag well, it can really throw off the angle of feed from the magazine, and there isn't much tolerance to play with.

 

[1KPerDay]

Were the CMMG kits you tried stainless or parkerized?

 

[socalbeachbum]

not even parkerized, just a really poor black oxide finish that started to scale and flake off. very poor finishing, the bore the slug hits right out of the case was really rough, looked to have been done with a hand drill.

they replaced it for me but it still did not feed reliably

 

[Johnny Lightning]

I have a stainless cmmg kit for my ar and it works great in my rock river upper but will not work at all in my bushmaster upper. The lower is a bushmaster lower that I use for both uppers.

 

[hatt]

If you had feeding issues with one AR, and not with another, it probably had more to do with the lower than the upper.

Exactly. I have a Ceiner that runs like a top in everything except when paired with an old S&W lower.

 

[Fishbed77]

My CMMG Sierra dedicated .22LR upper is fantastic. It's been incredibly reliable and is surprisingly accurate.

 

[CharlieDeltaJuliet]

CMMG. Upper with Black Dog magazines with metal feed ramps

 

[1KPerDay]

My CMMG stainless conversion has been flawless in 3 rifles FWIW.

 

[socalbeachbum]

so it sounds like tiny differences in uppers or lowers can create a problem. or in mags.

I ordered a Ciener. we'll see how it feeds.

 

[Fishbed77]

I ordered a Ciener. we'll see how it feeds.

I thought Ciener was out of business?

 

[CharlieDeltaJuliet]

I actually bought the CMMG Quebec-A. It is a complete CMMG AR in .22lr. The lower is a multi caliber (same lower as on their 5.56). It has never given me a problem. The only issue I ever had was with ProMags. They are junk and fail to feed multiple times per magazine...