CMMG 22 Conversion Problem.....

[jcountry]

I may just work some dremel magic on those lugs.

I checked PSA's BS return. I suspect they won't do nothing.

Really disappointed though. No excuse for stuff that far out of spec.

 

[fattboyzz]

I test-fit the conversion in another upper, and it works just fine.

After a more-careful look, I can see that the clearance into the throat of the chamber is wrong. The diameter between the lug channels is about 5 thousandths or so too narrow.

Never had trouble with PSA before, but this is clearly bad machining.

Mine worked great as a 556, just to tight for the 22 conversion.

It functioned great in an AR pistol with a 10.5 PSA upper. The 1-7 twist just had rather large groups at even 25 yards.

I built an upper with a Delton 1-9 twist 11.5 barrel . It has functioned great . The accuracy at 25- 35 yards is 1 - 1.5" and it eats even the cheapest ammo without being too dirty since it has no gas tube in the upper.

 

[jcountry]

Well..

I found out what’s going on.

Wrote an email to CMMG. Asked if they carry a small collar. They said they don’t.

They recommend just sanding or filing .003” off the brass collar.

Not too hard, but they say it’s an issue with PSA, Springfield and Radical. They say those places make that opening slightly smaller than milspec in hopes of improving accuracy.

Seems kind of silly for a short upper.

Oh well. I got a little project now

 

[Falcon1]

I can’t remember where I read it, but I do recall those conversions having problems in PSA rifles. Seems like a pretty quick and easy fix.

 

[ATLDude]

Well..

I found out what’s going on.

Wrote an email to CMMG. Asked if they carry a small collar. They said they don’t.

They recommend just sanding or filing .003” off the brass collar.

Not too hard, but they say it’s an issue with PSA, Springfield and Radical. They say those places make that opening slightly smaller than milspec in hopes of improving accuracy.

Seems kind of silly for a short upper.

Oh well. I got a little project now

Thanks for the feedback. Good to know.