NealeJW

Gentelemen, we have a quorum! Gonna lube it up and put at least another 100 rounds through it before I even think about doing anything else. Thanks for all of your help....

Aero Precision says the buffer weighs 5.6 oz and 5.3" long. I verified the length. Will try to weigh the buffer. Spring is 12.5" as specified.

My first semi-auto rifle, and I built it myself. Here's the build: Noreen Upper/Lower Yankee Hill Machine Gas Block - Low Profile Odin Works Rifle Length Gas Tube Ballistic Advantage Modern Series .308 Rifle Barrel - 20" Magpul MOE Stock Brownells BRN-10 Retro BCG VG6 Epsilon Muzzle Brake Aero Precision M5 .308 Rifle Buffer Kit I have put about 30 rounds through it and am consistently seeing classical symptoms of short stroking. I am using different sized magazines - 10 round, 20 round and 25 round Magpul Gen 3. So far, have tried 147 gr and 180 gr cartridges with same results. The bolt does not lock back after the last round is fired. Brass is ejecting around 3 o'clock for 147 gr and around 5 o'clock for 180 gr. Put a few rounds in a magazine, and the first shot is fine; brass ejects and next round is chambered. However, can't fire that next round because the bolt has not gone all the way forward - have to eject that round, manually lock the bolt back and then release bolt to properly chamber a new round. This is a standard gas block (not adjustable), so I am thinking the problem is not under gassing. The only thing I can think of is that the Aero Precision buffer spring is way too stiff. Anybody else have this problem with similar build? Any advice? Further trouble shooting?