Have any of you looked at the MOA on the Barretts? Not exactly what you want if you shooting at your standard military qualifying silhouette. The TAC .50 would be more suited for the application, where a Barrett with AP or SLAP would be wise for long range light armor shooting.
If you want reliable and long range effective - Tac Ops 700P package. .25 MOA, classic 700 action, around 1600$ + rifle. You won't find many rifles with that kind of MOA / $. Call Tac Ops, talk to Mike. He know's his shit (taking off the shelf rifles in the 1/2" MOA rating and guaranteeing 1/4" MOA when finished requires more then luck)
Not to be offensive about the topic, but have you shot from 800-1000m before? That's no stone throw, and .308 isn't exactly cheap. You might want to start with something cheap to operate to focus on breathing technique,form,etc.