I've shot a couple of black bear with the 260 gr Accubond. First one was at 306 yards, easy one-shot kill, with the rifle zeroed at 200 yards.
Essentially the trajectory is about the same as a 180 gr 30-06 load. Really doesn't drop all that much at 300 yards and still packs quite a punch. The 260 Accubond is a good bullet. Got the best accuracy with 69 - 70 grains of RL-15 and a Federal 215 primer.
I've used a 2-7x, a 3x and a 1.5-5x on my 375 H&H Ruger Number One. They all worked well.
Best of luck, Guy
