Hi. I just got a Ruger GP100 in .357 magnum, and am anxious to try to harvest a doe with it (already got my buck). I have cast for a couple .38's with good luck, but I was afraid my .38 bullets would be too soft for the .357 so I purchased a box of Missouri Bullet 158 grain swc "Action" bullets. They say they are brinell 18, optimized for magnum velocities. Well, have tried running them with unique, starting at 6 grains, and have worked up to 6.7 grains, which my Lee book shows is close to max. They shoot well, but I am getting quite a bit of leading right in front of the forcing cone. I just spent the last hour scrubbing all the lead out of my barrel, and now have it spotless again. I was wondering if I should try to push them even harder, if that would make them bump up to fit the forcing cone better? This is my first magnum caliber. I slugged my bore and cylinder, its .357, and the cylinders are .357 also. The missouri bullets are .358. Should I try my softer cast 158 grain lee rnfp bullets or would they be too soft for the .357. I want to try to push these to around 1200 fps or so to make a good deer load. I have unique, titegroup, #2, and 231 powder on hand. Any suggestions? Im kind of in a hurry to work up a good load because deer seasons soon over! Thanks