I have reloaded for a while now, but until recently I haven't had the good fortune to work with brand new brass. What (if any) prep work is needed or do I just tumble to remove any mfg. oils, neck size, load and shoot? Specifically Lapua in 300 Win Mag and Norma in .257 Wby Mag. What I usually do for my brass (once fired) the first time that I reload it is visually check the brass for any defects, trim to minimum length, deburr the flash hole, uniform the primer pocket and neck size only. This is for brass that has been fired in my gun only, and I don't swap brass from one gun to another. I'm starting to develope loads for my buddy's 300 Win Mag, and while he gave me some empty cases that he's fired (60 Federal, 50 Remington and about 20 Winchester) I ordered 100 new Lapua cases to make things a bit more consistent (plus I was advised by another member that it would be easier to get a great load by using good uniform brass) I thought I'd use the Lapua brass for the longer range loads and the Federal/Remington for the <200 Yd. whitetail loads.