Bnh 12 for up to 1000, Bnh 18-20 for magnum velocity. Some say Bnh15 is good enough but for 357 mag 158 @1250 I use Bnh18 from Missouri Bullet Company. Lasercast and Magnus are also good.
Addendum not necessary but I just use the same bullet for all velocities as I had some swaged cast from Hornady that leaded my GP100 something fierce even at 38 special speeds.
Thanks much for your info, Swifty!!
:-)
Crab