My experiance with Lee 50 cal 320 gr. R.E.A.L. bullets is this. I bought them cast from a seller always on auctionarms.com. Caster said shoot them dry un lubed. My gun is a cheap CVA Buckhorn Magnum $130 with $29 3x9x40 Tasco scope. 24" barrel, shotgun primer, 1/28" twist. All loads by black powder volume, not wieght. Loaded 80gr. Pyrodex RS By volume. Gave 1500 fps and very accurate at 50 yds. All 3 shlots touching. Moved to 100 yds. No shots hit target. Moved back to 75 yds. - key holing. Moved up to 100 gr. and 100 yards. 12" group. Bullets still unstable but no key holes. Moved up to 120 gr. See target. 1840 fps. Moved up to 150 gr. Just as accurate as shown target but 1950 fps. I shot 43 of them with no noticeble leading but I was wire brushing once down tube between shots. Hope this helps. Caster's bullets were perfect. He said 100% lead.