AR-15 Conversion Bolt Problems

[fyrediver]

I took my AR to the range the other day with it's CMMG .22 LR conversion bolt and 2 new 10 round magazines to check for accuracy and dependability.  I was hoping to be able to use my AR with conversion as a back up gun for  Appleseeds. 

I think I'll stick with my 10/22 for the AQT.  If I decide I must have a back up gun it'll be another 10/22.

The accuracy at 25 yards was sufficient to score Rifleman on the AQT.  Groupings opened up considerably at 50 yards.

The dependability, however, left too much to be desired.  I had many failure to ejects with the bolt conversion.  Several were such that I had to remove the bolt to remove the spent and now stove piped casing.  The spent casing would become stovepipe jammed in the spring loaded bolt assembly.  I didn't have any failure to fire at all, but many ejection issues.

I tried both the CMMG 30 round magazines and the new 10 round ones I purchased and both had the same ejection issues.

Not sure how dependable a dedicated .22 LR upper would be but for the same price I could completely outfit another 10/22 and then still buy ammo for many Appleseeds and practice sessions!

[jmdavis]

mine has been 100% reliable with Minimags.

I shoot minimags in both 1911 conversions and AR conversions. No problems with 1000 rnds through each.

CMMG specifically advises owners not to use Remington AMMO. What were you using?

[fyrediver]

I was shooting both Minimags and Federal bulk.  Those were the only two types of ammo I had with me at the time.

I'll clean it up and give it another try with only the minimags to see how that goes.

Thanks for the advice; I'll give it another try.

[jmdavis]

I also run AR's  very "WET". Using LSA they are just shy of dripping.

Mike

[Old Dog]

While I haven't had exactly that issue I've read about others having it (arfcom threads) and they said it was sometimes due to the empty hitting the outside feed lip on the  magazine and bounding around inside.  Since you tried both magazines though it may not be the problem with yours.

Like Mike said, I use more than enough oil on mine.  I'm getting dirty anyway, what's a little oil on my hands (wear safety glasses so it doesn't blow back into your eye past the charging handle.

Like other .22 rimfire issues, trying different brands of ammo can sometimes solve an issue.  Many folks badmouth Rem. Thunderbolts but they work great is some of my .22's (and shoot great, too).  I use Rem. Golden Bullets in my AR15 (with CMMG conversion kit) while my son's AR15 likes Federal bulk pack (Ceiner conversion kit).

There are so many brands of .22 ammo out there to try.

[AZRedhawk44]

I don't have a conversion bolt, I have a full dedicated CMMG .22LR upper.

I found that if I trimmed 2 coils off the recoil spring I got much higher reliability out of Federal bulk ammo.  Minimags/Stingers/FedAutoMatch all seemed to run fine, otherwise.

I run mine pretty dry.  I lube it with a white lithium grease, very lightly.  That's it.

The dependability, however, left too much to be desired.  I had many failure to ejects with the bolt conversion.  Several were such that I had to remove the bolt to remove the spent and now stove piped casing.  The spent casing would become stovepipe jammed in the spring loaded bolt assembly.  I didn't have any failure to fire at all, but many ejection issues.

I tried both the CMMG 30 round magazines and the new 10 round ones I purchased and both had the same ejection issues.

I'm running Black Dog Machine magazines.  I'll admit to much better reliability out of the 26rd mags (supposed to mimic size of a 30rd .223 mag) than the 15rd mags (supposed to mimic size of a 20rd .223 mag)