RickF has it right. Use 300 Win Mag brass. (He is right on the other stuff too).
Also, for cheap range practice, I load pistol bullets intended for .38 Special and .357 Magnum revolvers. If you want, you can load these bullets up to fearsome velocities.l One (novelty!) load I once used had 125gr Hornady pistol bullets (intended for 1200fps) flying out at about 2900fps. More realistically, a 180gr pistol bullet makes a reasonable practice round at fairly low cost.
I also have a .375 H&H, but you have to cast your own bullets to have cheap range practice. With the .358 Norma Mag, a box of pistol bullets and you are good to go!
John
