If those 300's were heavy enough guns, the recoil should not be much different from a .270. Did he say why he was concerned about recoil? I got hurt a while back and my doc took me off magnum calibers and anything else with significant recoil. I now shoot a .223, 7.62X39, and (this year).30-06 managed-recoil. I don't know how the new .30-06 ammo will work out, but I have been told the recoil is similar to a .243. If it was my job, I think I would have told him he needed a different gun each for deer, elk, and moose and maxed out my commission!