As long as you use a plastic, rawhide, or rubber mallet/hammer to initially drive the round ball into the barrel it will absolutely do no harm. Once in the barrel use a wooden dowel, or nylon if you can find one, and tap the slug through the barrel, it will go far more easily than you think. Absolutely do not use a steel or brass hammer to start the slug!
But, we are back to the same question, how are you going to measure the slug?
If your cast bullets, un-sized, fall through the throats of one gun you can't do anything about that without a different, larger mould. For the other one, slug the cylinder throats (you can measure a round slug) to determine how big they are. If the bullets are no more than .001-.002 larger just shoot them un-sized. Get a sizer die large enough (.454 probably) that you can lube the bullets without sizing them. It has to be close to bullet diameter or you will have too much leakage. You will be surprised how little pressure on the lube screw is needed to lubricate a slightly smaller bullet.
Naturally, if the throats in the tighter cylinder are .451 (not likely) and your bullets cast .456+, you are going to want to size them to .451-.452. Note though, at least with harder cast bullets, a die will typically size approximately .001 larger than it is marked. It is because the die stretches under pressure, not because the bullet "springs back" like many seem to think. Even "hard" lead alloys are relatively soft and easily deformed under pressure.
|