Took my DPMS 1:7 upper to the "rifle" range today. Until now, all the testing has been at an indoor 25M range, and I needed to zero the TA31 at 100 yards.
From my other ACOG sighted rifles I had already determined that of the three types of M193 ammo I have on hand, the Fed XM193 is generally the most accurate, so that's waht I used.
First group from a cold, dry, clean brl measured 1.21" Adjusted the scope 1 click left and 24 clicks down and the next group measured .89" and hit point of aim.
With the TA31 sighted in an 100 yards, using the top of the donut, the center of the donut was on at 200 and the bottum of the donut was on at 300. I confirmed that with about 70 rounds fired at steel plates at those ranges. Hits at 400 were a little tougher, and hitting the mountain lion target at the 500 meter line was iffy, only hitting it about 1:3 shots.
Cant wait for that NATO spec 77Gn OTM ammo to come in....