If I knew exactly what you are shooting I could give a better estimate. For instance a .357 mag with 158 to 165 gr cast: 2 to 2 1/2 grs Alliant Red Dot/ Promo should work. I have used 3grs of Red Dot with 160g cast for years as a target ( 50 yds ) load in the .357 mag. So try 2 1/2 grs of Red Dot to start. See if that works in your piece. If so try 2 grs. l believe that 2grs will drive the bullet out of the ( 6" ) barrel . Also if you fill a cardboard box full of tightly packed rags to shoot into ( 5' ) you can recover every bullet you shot for a remelt. If you give me more info I could give you specific info. I've been doing fire lapping for over 30 years & am very glad to help. If needed I would be willing to cast some bullets for you, you just pay the postage.dom how much powder ,look up cast loads and shoot the minium charge?