The TA31's ACOG aka Army issue? I've had a bit of experience with them and love them. The Air Force PJ zero target is the best thing I've seen to dial one in. You basically have to keyhole your shots to "zero", but it's a great tool to learn the ACOG. I will say the ACOG will hold zero and keep it there. After all the banging around in the truck and Bradley, I never had a "misplaced" shot. Only downfall I ever had was utilizing the optic at night, or in a dark close environment. Not the best when your #1 in a breach, but thank God for 12 gauge shotguns. Anywho, we had a couple gun fights near Sadr that were beyond the 300 meter range. If it weren't for the ACOG's on our rifles, we might not have caught their muzzle blasts. If you measure up the target inside the elevation lines, you can SWAG a shot.
I may have a source for such products. I'll call and see what he may have. Any preference on optic or you want whatever you can get?