depends on the cartridge and ofcourse shot placement. I loaded up some light loads in 308 with 42 grains varget under a 165 grain sierra BTHP GK for my lady to shoot just so she gets the idea of shooting a high power rifle. the rounds actually group decent and chronographed a little over 2500 fps if she ever decided to hunt with me they would deffinately be adequate to take big game and at 300 yards they should still be producing well over 1000 ft lbs of energy which seems to be the minimum energy margin when deciding if a caliber is adequate for big game.