My Missouri Bullet Company 300 gr. lead .452" bullets (which have a Brinnell Hardness Number of 18) when loaded over 28.0 gr of W 296 to a velocity of about 1430 fps keyhole into the target at a distance of 10 yards or more. This amount of W 296 powder is 3.0 gr over the Max listed in the Lyman Cast Bullet Handbook, but it is the same load at which my 300 gr. lead Beartooth bullets which have a BHN of 21and have gas-checks perform very well, and I think I got that loading from the Beartooth LoadSwap webpage, but it is not operating now so I cannot confirm that. I am guessing that the velocity is too much for the hardness of the bullets without gas-checks, stripping the lead instead of imparting the necessary spin required to stabilize them. Unfortunately I loaded 100 rounds before testing them, and I would rather not pull all of those bullets. Any thoughts or insights would be most appreciated! Dogman 45