bullet wt, you CAN'T double the powder charge. Well, you can, in the case of the .45 ACP, IF the lighter bullet has a HUGE hollowbase. That hollowbase serves the same function as a .100" longer cartridge case does. It makes more room in which to BURN powder. A 6 gr charge of bullseye is no big deal under a 185 gr jhp in .45 ACP, and 12 grs of Bullseye is no big deal under a solid tin, hollowbased 90 gr swc, )2000 fps, 4" barrel)either. Yes, it's a 'hot" load, but so is the 185 gr bullet at 1100 fps (in a 4" barrel). it is NOT, however, at ALL dangerous, in a fully supported barrel. The .45 Super case is NO thicker, AT ANY POINT, than is R-P .45 ACP brass. Yet they safely get the 185 gr jhp to well over 1200 fps in a 4" barrel, in .45 Super ammo.