Range report and hopefully helpful info for your AR15 .22 conversion kit

[Old Dog]

I'll keep it short.

Issues with Black Dog magazines (2 new ones) with both a Ceiner and CMMG units today.  Issues were failure to chamber (regularly) and a few failures to extract.

Use of the factory Ceiner mag showed it was a mag. issue, not a unit or ammo issue (Remington Golden Bullets).

Close look at the bottom of the conversion units (as well as some mag in/mag out bolt manipulation) showed the bolts were rubbing the top of the right feed lip.  The bolt has two grooves in the bottom to clear the mag. lips and for some reason the groove on the right side is much shallower than the groove on the left side causing the bolt to rub the top of the right lip.

Some slow scraping with a pocket knife followed by testing in the rifle (did this several times as I didn't want to take off too much) resulted in a Black Dog mag that would run through from full to empty with no issues.  Repeated it with the second Black Dog magazine and now have two BD mags. that work great with the Ceiner unit.

My brother ordered a service grade H&R M1 from the CMP last spring but never got to shoot it before we lost him.  I ended up with the rifle and took it out of the box to shoot today.  At 25 yds. the first four shots from the clip (my reloads) all hit about 1" above the POA.  I put the last 4 from that clip plus the next clip into the second target from standing at a rapid pace.  It's a nice shooting rifle.  Sighted in right out of the box.  Gotta be happy with that.

Little file/info on the Black Dog magazine problem.