I agree with the pronghorn antelope recommendation. Since shots may be moderately long on antelope, use an accurate rifle and cartridge combination. The mini-14 may not qualify on the accuracy issue. Also, I agree .243 ought to be a minimum for pronghorn antelope (though I'm not disparaging .243 for antelope or suggesting it is marginal -- it is very suitable in my opinion), and if the mini-14 (I don't know much about this -- is it a .22 caliber?) is lighter, than this is another count against it for antelope. The .280, on the other hand, is entirely adequate in terms of power and is reputed to be accurate.