Ok, so I polished the chamber, and put the original buffer tube, buffer spring, and buffer back on the gun. Got the donuts for the extractor spring, but didn't put them on as I have a sprinco extractor spring that has another spring inside it. Took it to the range. Shot off 10 rounds of Federal 168 grain .308. Swapped out my p-mag, and starting going thru that mag and had a FTE. Cleared and shot the remaining rounds. Grabbed a handful of some Brazilian 7.62 147 grain, and loaded them up. Every round was an FTE with a new round jambed into the bottom of the spent casing. Shot a single round by itself. Bolt locked to the rear on the empty mag, but the casing was still inside laying on top of the magazine. Pulled out some Remington 180 grain .308. Zero FTE's. Worked like a champ. I would shoot a few rounds of that, and put in the 168 Federal, however these started FTE'ing every round too. So it appears with the heavier grain bullet, no issues. Lighter grain, FTE's galore. On a side note, I can tell a big difference using the stock buffer and buffer spring compared to Slash's Heavy Buffer and buffer spring. I'd love to use those instead as they cut the recoil way down, but I'm trying to get back to stock to work thru this problem. My gunsmith told me he could put the stock gas block back on if need be to try and figure out zee problem. Any ideas?