I shot (and hit) a 1k target on Saturday (using a friend's LMT MWS in 6.5 Creedmoor). It really wasn't THAT hard. Get the dope figured out, get the fundamentals right, and send it. Rreading wind well still eludes me. However, within a couple rounds, I was hitting about 50%.
750 with a .223 is also not difficult.