As it is with nomercy, I have around 30,000 rounds through my Wilson Combat with the original BCG and on my 5th barrel. I've always used an AGB and fine tune it to the rounds built every time. If I change a powder, bullet, or even a primer I re-tune the AGB. My 6.8 gets the same treatment though it has only seen around 4,000 rounds and it's getting close to a new barrel need and will probably be going with a Black Hole for it as that .338fed of the old mans is exceptional. A lot of people are under the false impression that over gassing is a good thing, that it will ensure your operation of your system when in fact it's harder on your entire system, creates more recoil, and seriously dirties up your rifle. And if you ever put a suppressor on it, well lets just say a bad day will come soon but then you are talking about needing a heavier buffer spring as well as closing off the AGB a bit to prevent short stroking. The make it short, AR's are fun but they can be pickier than a prom date sometimes. That is if you are really serious about your hardware.