The shorter barrel makes it a little more difficult to work up a good load. You won't get the highest velocities the cartridge is capable of. I forget the rate of twist, but I used 50gr highly frangible bullets. But I don't think this shooter is using FMJ's. The kills/wounded ratio is too high, or he's putting the bullets where he wants them.
That doesn't mean much. To an unfamiliar person a contender might be a rifle. It has a long enough barrell that it could cause one to think "rifle" and the scope, if it has one, could cause one to think "rifle".