I am going to be building a double rifle as my final project in my machining school (if I can find a blasted blueprint for a boxlock action, if anybody knows a source please tell), but I am having a hard time choosing a caliber. Originally I was going to use the .375 H&H Mag. as my cartridge, but according to Ellis Browns book, it is a high intensity round as far as pressure goes. My other two options I am looking at are the 450/400 NE 3", and the 450 NE. I wish to have answers broken up into categories, such as strengths and weaknesses of each, ease of, cost of, and availability of, reloading and reloading supplies, recoil (I am going to be putting LimbSavers AirTech pad on this so it should take the recoil down a bit), and any other info that would help. Any help on this is greatly appreciated. Thanks.