3.5" Rocket launcher, AKA a Bazooka in 1969 was probably the biggest. For rifles I've put a few rounds through an AR-50; which is a big 50 BMG bolt gun. Didn't kick that bad, as it weighed about 30 lbs IIRC. Have shot my buddies braked 340 Weatherby a number of times, as I reload for him, and that wasn't bad either. And let's not forget those 3" 12 ga. slugs and turkey loads fired from pump shotguns. I'd rather shoot my buddies 340.
