Thanks to the thrice-great customer service department at Trijicon (I knew the price was so high for some good reason...) My TA-31 came back in today.
They fixed the problem with it hitting 4-feet left at 100 yds, I got to take it out today for some fun.
The range was crowded with a bunch of stink-stick shooters, but I squeezed some targets at 100 and 200 yds.
I sighted in the ACOG to hit about 2" high at 100 (middle of the top part of the band making up the donut) Expecting my shots to be about dead center at 200.
My 100 yd targets were everything I could have wished for. At 200...well, there was still a little to be desired, though that may be an operator problem since it was cold out and I'm a wus, so I was rushing my shots.
I'll have to check out the bullet drop chart for my ammo/barrel combo and see just where I should be sighting in at.