I'll just keep my .243. Thanks anyway.

Backup for dangerous game? I'd think you'd want to be able to shoot with your eyes open, and have at least some hope of retaining possession of your weapon in case you need to try to jack another round into the chamber for a quick follow-up. I certainly wouldn't want to be using a weapon that would knock me to the ground, fling itself 10 feet away, and render me into a pre-tenderized quivering lump of prey...