I've been looking to purchase a good hunting rifle able to reach an easy 300-400 yards. I already have my 308 which is very capable but now I'm looking to go bigger. I've been reading up a little on a .338 Caliber yet I'm still unsure of the differences between an Ultra Mag and a Win Mag other can casing length and PRICE. Is there anyone out there that can put some of the magazine talk into basic terms that I might be able to understand?