They aren't bought with consideration too ammo costs, getting the most from small amounts of powder, etc etc... They are bought to be shot at LONG ranges, to kill like lightning and the grandest of ALL American reasons... just because you can!
Aah, but there's the heart of this issue. He didn't buy that gun, he won it. If someone buys a 30-378, they know, or should know, what they are getting into. Cost, recoil, blast, etc... But he won the gun and apparently doesn't know much at all about the cartridge like someone who was about to drop $1200 on a TRG-S would. I'm giving him the facts so he can make an informed decision about what he wants to do with the rifle. If he accepts the negatives and keeps the gun, I don't have a problem with it at all.
Mike