Great history and information gents. So the ballistics were certainly achievable. I always found despite being smaller there was something obscenely impressive about the 378wby even alongside its bigger brothers. I think Roy adding a couple numbers extra to the name helped too(460 for 458 and 378 for 375, 340 for 338 etc), he knew how to market a calibre name. Interestingly when the 416 came out which was later, he stuck with .416...
Ron, that silver packet with the basic writing must be at least early/mid 90's? Thats the ammo boxes I ordered with my 460.
