Hey guys I need some help. I'm looking for the best possible brass that I can buy for my .338 Win mag Remington 700 Sendero build I'm in the process of. I read where Lapua brass is the best on earth but also that they don't make any in .338 Win mag, yet they do in .300 Win mag and that I could buy the .300 and neck it up then full length resize in my current RCBS FL .338 die and be good to. I'm new to all this and don't have the slightey clue as to where to begin so any and all information is great appreciated. Thanks guys.