All my experience with casting lead balls was done over a common gas stove with an iron pot, a dipper and steel casting mold. I tried aluminum molds because they would heat up faster, but found that, conversely, they also cooled right back down equally fast which gave me a continual varying mold temperature and balls that weighed all over the place. So I settled on steel molds and never went back.
I would heat the lead till it was quite liquid, poured like water, I would drop in a bit of bees wax and after the smoke cleared, would skim off the crud that floats to the top.
I would keep the mold right by the heat source so it would heat up along with the lead. When I thought everything was ready, I would rapidly cast about 30 balls or until the balls began to look bright and smooth – no funny lines on the outside surfaces – at which point I would take the balls cast and drop them all back in the pot. I would then proceed to cast balls as rapidly as I could, or until my arms began to weaken from the repetitive action.
When the phone rings – it will always ring when you are casting balls – I would lay the mold itself in the lead where it will float like a cork – and then go to the phone. This way your mold will not cool off and put you back to square one where you have to begin all over. Why did I cast my own lead balls? Because I knew that every ball came from the exact size mold. You don’t know that about purchased cast balls.
Why didn’t I just buy those excellent looking swaged balls? Well, I did do that for a while until I got a bullet scale and began to fool around with the weight variations in balls and the effect of that variation on accuracy.
I had been purchasing cast balls from a gentleman and I found that all the balls from that source ran only about 5% on the light weight side. Swaged balls from both of the most popular sources on the other hand ran from 20 to 22% on the light side.
Applying logic to all this it occurred to me that if you have two lead balls the exact same size, made of the identical material and one ball was lighter, something had to be missing from the light weight ball, or there was an inclusion of some other material that weighed less than lead. In either event, if the missing lead, or the included material was not dead center on the axis around which the ball spins, you have an off balance ball. The further from the axis, the greater the effect.
Well, so what?
I finally decided that a light weight ball was any ball that weighed more than 1 grain less than the heaviest ball. I was casting .445 balls. Had I been casting .31 caliber balls I would have made that a half grain variation.
I hate to ask you to do this, but go remove one of the wheels off your car or truck. Weigh that wheel. Surprisingly heavy isn’t it. Now remove one of the wheel weights and weigh that. Insignificant compared to the weight of the wheel isn’t it?
Don’t replace the wheel weight, but remount the wheel on the truck or car and go drive at about 60 miles an hour. Notice a pounding sound? The slight difference in weight has thrown your wheel out of balance and the heavier part of the wheel is leaping away from the axis on which it is turning.
So, too, does the light weight lead ball try to leap away from it’s axis. I hope you marked where the wheel weight was placed so you can remove the imbalance by putting it back where it was doing its job.
Since I began weighing out lead balls I have not had a single flyer in about 15 years of shooting after the discovery. I have heard from a SWAT team member who shoots only cartridges that he has personnaly loaded himself, that by weighing out the copper or steel jacketed projectiles he would eliminate 800 out of a thousand because of weight variation. When you are shooting at the villain behind the hostage, you really can’t afford a flyer.
Another thing about casting your own lead balls; Remove the handles from the mold and they make the best nut crackers for hazelnuts, or filberts that you ever saw.
And no more flyers.