I've used all sorts of scopes to take big game, running from a few fixed 2-1/2x's to one 4.5-14x. The variables were generally set on relatively low magnification (the 4.5-14x was set on 6x), but not always. Have shot a few animals with variables set on their top end, but that was never more than 9x or maybe 10x.
Have killed a bunch of big game with fixed scopes from 2.5x to 10x, but most have been 4x or 6x. In fact I'm sure I've taken more game with fixed scopes than variables.
Last year I took 11 big game animals with the following scopes:
4 feral pigs--2.5-10x Zeiss set on 6x. The biggest was a trophy boar shot running twice, once at maybe 80 yards and once at 10 yards.
zebra, wildebeest, hartebeest, impala--All with a fixed 4x at ranges up to about 200 yards.
Cape buffalo--A fixed 3x at 30-35 yards.
Doe pronghorn--A fixed 6x at 175 yards.
Doe whitetail--A fixed 4x at 100 yards.
Buck whitetail--2-7x variable set on 7x, 30 yards.
I also shot another doe whitetail with an aperture sight and front bead at 50 yards. Usually I kill at least one animal each year with irons, and sometimes several more.
