All week I've had my varminter and my coyote-getter ARs in the truck but could not get off work early enough to go shoot.  Finally got there Friday, my day off, but the race track people were there so I could not shoot 300-600 yards. (Rounds going over their heads makes 'em nervous.) Our range shares property with the track, so this is not uncommon, but the season closed two weeks ago so WTF were they there for?  So I shot both ARs at the 100-yard pistol range.
Forgot my targets, forgot my 69gr loads for the varminter, the 55's for the coyote-getter need to be crimped more (heads move back into the case if they hit the feedramps just wrong) and the coyote-getter is a single shot.
Looks like a short-stroke, but the FAQ checklist link is still dead.  The upper ran ok on my Bushy/Jewell lower, so I think I have a buffer or spring issue.  I've disassembled and checked bolt and carrier, gas tube, etc- all look ok.  I don't think the tube is hitting the key, and it short-stroked with handloads and white box commercial.  The carrier stops about halfway back.  If I pull on the charging handle the brass ejects fine.  If you lock the carrier back the bolt doesn't look like it clears the rear of the magwell- not going far enough back?
Oh yeah, while I was there two people came by to scavenge brass, WITHOUT HEARING PROTECTION, in the bay next to mine.  Smart.

1911fan

This may sound fairly abvious, but have you also checked to make sure the gas block is aligned properly with the port in the barrel? I ask because I had similar problems to yours with an SPR I built. It turned out that when I mounted my PRI sight up against the shoulder on the barrel, it wouldnt align correctly and all I would get is a slight unlocking of the bolt from the recoil. I ended up moving it up just a hair and now it runs as it should.

Could be, as the upper is all homebuilt with a four-rail gas block I put on; I'm famous for installing all my scopes with a cant.  But the upper runs fine on another lower.  While sitting here sipping coffee and enjoying the board, I had a brain fart.  Problem is in the lower, duh.  I swapped lowers and now the bolt/carrier on my coyote-gitter retracts about 3/4" + further back, and the bolt on the upper I swapped to does not.  Something is keeping the buffer from cycling far enough rearwards to allow the bolt to travel far enough back to eject.

Igor!  Get the tools ready!! Ve are performing ein buffer-ectomy!!

1911fan

Post-surgery report:  The non-cycling lower (milsurp butt, rifle length) had a 6 1/2" buffer in it.  The cycling lower had a fixed telestock with a 3" buffer.  I swapped buffers and now they both manually cycle identically.  I didn't check the springs, thogh.  Should I?

Quoted: Could be, as the upper is all homebuilt with a four-rail gas block I put on; I'm famous for installing all my scopes with a cant.  But the upper runs fine on another lower.  While sitting here sipping coffee and enjoying the board, I had a brain fart.  Problem is in the lower, duh.  I swapped lowers and now the bolt/carrier on my coyote-gitter retracts about 3/4" + further back, and the bolt on the upper I swapped to does not.  Something is keeping the buffer from cycling far enough rearwards to allow the bolt to travel far enough back to eject. Igor!  Get the tools ready!! Ve are performing ein buffer-ectomy!! 1911fan Post-surgery report:  The non-cycling lower (milsurp butt, rifle length) had a 6 1/2" buffer in it.  The cycling lower had a fixed telestock with a 3" buffer.  I swapped buffers and now they both manually cycle identically.  I didn't check the springs, thogh.  Should I?

I wouldn't worry about the spring... if it works, it works.  If the springs are not beat to hell (is that possible?), are lightly lubed, (lightly!), and functioning fine with the 3'' buffer, i'd say you are good to go.

Igor, Ve have veenished ein buffer-ectomy.l

- BG

Ja, und ze bufferectomy iz a komplete suksess!!

Coyote-getter functions normally, slow and rapid fire.  Why would one long buffer not work in a normal butt, and work in a fixed tele?

1911fan, confused