I dont personaly own a 338-378 Wby but do have a 30-378 Wby Imp and the plain old 378 Wby.While both are more exspensive to feed than say a 300 RUM or 375 H&H, they are cheaper than my 416 Rigby fodder.

Both of them ROCK!.....on both ends......

I have most bases covered or I would have a 338/378.
I would try to find one to shoot first, the bigger boomers are not for everyone, that's why you see them for sale with a nearly full box of shells....doubleA