Longest shot on a buck with a fixed 6X was 330 yards. Woodchucks to about 400 and yotes about the same. I shoot 600 with a fixed 6X on the range.
I've killed more stuff further away with a fixed 4X;longest mule deer about 500 and ditto on elk.An elk is the size of a house and shoo in with a 6x at 500 yards.
But like Royce, I like more power these days in open country.