My Springfield M1-A flattens the case mouths too. I wonder if this is just a result of .308 gas guns. I don’t recall if my AR-10 did the same.Cofisher wrote: ↑Fri Jan 13, 2023 7:57 pmWent to son's last Sunday. Rifle performed flawlessly. Dang! That big boom is impressive. Next up is some gas block tuning. Cases are coming out with some flattening at the mouth. I believe it is related to an overgassing. I've studied the procedure for adjusting the pressure. Will screw down the aperture until it improves.
Hoping to shoot Sunday again. Have all the parts to assemble a target frame that will allow paper and steel targets. Getting closer to some serious shooting.
EDIT
I just checked some fired brass from my M1-A and the case mouths are NOT flattened. So that leaves be to believe it was my old AR-10 that flattened the case mouths.