Gelka... from casting for a .44mag many years ago, a couple of suggestions... get a mold that casts for gas check to be installed, and use gas checks...then find the ball process powder(where the grains are tumbled in a flame retardant like graphite, regardless of the shape... I always like to use Winchester powders) that suits your objective...once you cast and size a projectile, drill a hole through one, along its axis and run a 'stick' through it... test this clearance gage in each cylinder hole and see if there is enough clearance forward of the chamber to not squeeze the bullet before it enters the barrel...I used the Hoch bullet lube formula, but that was 35 years ago... leading for me, was typically the result of the base of the bullet being burned off... and tumbling was the best indicator...follow the safety precaution,, all lead compounds are poisonous...