I shot a 12 inch pull, 8# 338 Win Mag with a full load of powder behind a 250 class bullet. First shot, from bench, hurt. Second shot from the bench resulted in tears in eyes and a quite lengthy one armed flapping rain dance.
I immediately fell in love with brakes. Swapped a 338 RUM in to the action and full tilt, 2700+ FPS MV w/300 SMKs with tupperware stock and brake are a dream. 105#, 5' 8" pole of a grandson shoots it prone with no problems.
I'd recommend going the 338 RUM route and go the brake way. Sleep with the brake for a while, you'll fall in love with it.
Its really worth it to spot your shots even when some times the rest isn't all that good.