Finally got back out to the range today. Busy place as they had a cowboy shoot going on.
I've been having an alignment issue with a (ProMag) scope mount for my M14 (M1A), and think I have finally have it resolved.
After red-dotting the neighbor's houses (~50-100 yds.) for the last several evenings, I finally had a chance to get the gun back out to the range with the rear of the scope shimmed with a strip of .020” brass.
Unfortunately, I had fooked with the iron sights after my first (successful) outing with the gun to align it with the laser bore sighter's dot. It was “shooting” way low based on the dot and I adjusted the rear sight to bring it up. Wrong move. Once I got to the range, I have no idea where the initial rounds were going, but I damn sure wasn't hitting the paper. I kept lowering the rear iron sight back to where I remember it being and I finally brought it in. With the gun in a rest, I then adjusted the scope to match it, and bingo – I was right in there. I was a happy camper.
Next up was to change the scope from the M1A to an AR with a 7.62x39 upper. I have never had any windage issues with the mounts on either rifle, so I knew it was going to strictly be an elevation adjustment. After about three rounds, I finally had the scope's hairs adjusted to where those rounds were right in there too. Opposite ends of the scope's latitude of (elevation) adjustment, but I was kind of expecting that.
It was a good day. I am convinced that the ProMag mount has a problem, but I also think the “problem” was being compounded with the end of the flash hider not being in correct alignment with the bore. That was also throwing the laser bore sighter off confusing my feeble brain.
At some point I may pull off the hider to see what a nekked barrel will show, but for now, the guns are going away. I have bikes in the shop I need to work on.
THAT, was my day.