I've never had any trust in buckshot except for gaurd duty.
: My cousin lives back East in Ontario and tried 00 buck for whitetail deer - once. He failed to kill his buck at a paced off 30 yards. The deer was never recovered. He switched to slugs and never fails to fill his tag now. Past 10 yards, buckshot has proven fairly ineffective on black bears, and are not at all recommended on griz unless the muzzle blast singes fur. 1-1/ ounce slugs, and preferrably solid round balls do much better on both.