I have taken antelope in WY and SD with both 6.5JDJ and 6.8SPC in Contender's, and both work well. My self-imposed max range is 200 yards, and have always been able to get within that range. Larger calibers will likely stretch the range a bit, but it seems more sporting to use an old hunting term called "stalking" to get within a reasonable firing distance than "sniping" at them at extreme range. However, what is "reasonable" will be debated.