Looks like 3GN will be hosting some long range matches in my area next year. One of the ranges is limited to 500, but another not too far away will go out to the full 750 yards.
Targets at that range will be "big", like 18x28 plates, 16" circle, etc.
Due to range limitations I've never pushed past 600 with my 5.56(or any rifle for that matter...). The calculators show that my current 16" + Mk262 combo will go transsonic around 675-700 yards. Velocity at 750 will be ~ 1150-1175 fps depending on weather.
My question is: what should I expect to happen? I've seen 55gr rounds go completely erratic at 600. Will the same thing happen with 77 SMKs? I don't need pinpoint accuracy, but I do need to be able to hit a silhouette.
I don't particularly want to invest in a new barrel or caliber for this game. The current combo works great out to 600 yards and I'm happy with that. There is some possibility that the newer Black Hills 5.56 TMK loads will push a bit farther out before going transsonic, but they are awfully spendy at ~$1.10 per round and I don't reload.