Many of you know I purchased a Ta31F about a year ago. Its been sitting in the safe lately due to my interest in NRA High-Power and all funds (and trust me, i have trouble with funds) going to set up my hodge podge High Power A2. The utility of the ACOG comes from its quick ranging features and the capability to drop rounds on targets at x,y, or z meters away. From what I researched, the Ta31F is calibrated for 62 grain ammunition fired at a velocity of roughly 3000 fps which mirrors a 16 inch carbine. My 20 inch AR15 is not calibrated for said ammo, but I purchased the TA31F anticipating it may go on a 16 inch carbine one day. I still don’t have a carbine. My range doesn’t allow steel core 62 grain XM855 on our steel targets so there goes using the very loading the TA31F was calibrated for!
The stuff you just don’t think about until… DANGIT!
Running 55 grain XM193 loadings in my 20 inch rifle were not matching up with the BDC past the 400 yard steel. I tried it. I had no idea where I was hitting at 500 and 600 yards and I couldn’t hear the steel gongs ring. While the Ta31F is versatile, would I have been happier with a TA01, TA31, or other full-sized ACOG? What tempts me is how easy it is to buy 55 grain XM193 which is the loading used to calibrate all full sized ACOG models unless designated otherwise. Well, the TA31F is designated otherwise.
Well, if I want to push my rifle, I knew the 55 grain stuff just would not cut the mustard in the wind. I want to run my ACOG in a DMR class one day, so I had to find a loading that matches my TA31F to make it useful. Funny enough, it appears that my 69 grain Sierra match king I whipped up for my High Power A2 rifle works very well with the TA31F BDC.
So If your shooting a 20 inch barreled AR15 on a range distanced in yards with a TA31F, a pokey 69 grain SMK loading hovers right at the BDC all the way out to 800 yards. This setup will shine for longer range shooting since the 69 grain SMK should buck the wind much better than 55 grain ammo. While I wish I did have an Ta01 to easily match Xm193, the Ta31F will likely yeild better results with 69 grain ammo at these distances. Since I don’t have a carbine at the moment, the TA31F isn’t grab and go easy… but since I found a nice match with my 69 gr SMK I think I will enjoy it much more.
My 600 yard range is closed for winter range updates, and I hope they will be done soon so I can try this out. My ATN 5x gun cam is ready see where the hits are at.