Canute Rex
40 Cal.
- Joined
- Apr 19, 2012
- Messages
- 397
- Reaction score
- 303
A while back I posted about my first try at round ball mold making. A friend of mine made a rifle from a barrel that wasn't quite 50 caliber. He needed a mold that would throw a .480" or ..485" ball. I got a 31/64" ball end mill and gave it a try. It was not perfectly round. The cutter was off center so the diameter varied by 0.010".
This time around I tried a slightly smaller ball end mill (15/32") and used a previous attempt at a mold half to center the cutter. I was cautious about the depth of cut and cast a ball that looked like a moon pie. I measured it and figured how much more depth I needed. Finished the last 0.010" by turning the headstock by hand to avoid chatter marks.
I ended up with a mold that casts balls around .472", varying a thousandth either way depending on which direction I measured them.
You may notice if you look closely that the sprue hole isn't centered on the divide between the halves. Don't try to add and divide decimals in your head late in the day. I had to machine and file out the overhang on the deep side. The sprue looks wonky but the ball itself is fine.
My friend is going to try out the balls I cast and make some more if they work. The previous oblate spheroid ones from the uneven mold did group on the paper, but I was dissatisfied.
I borrowed 8-32 screws from a Lyman mold. I drilled and threaded the mold blocks so they can be used with standard handles. I made these handles out of some scrap.
This time around I tried a slightly smaller ball end mill (15/32") and used a previous attempt at a mold half to center the cutter. I was cautious about the depth of cut and cast a ball that looked like a moon pie. I measured it and figured how much more depth I needed. Finished the last 0.010" by turning the headstock by hand to avoid chatter marks.
I ended up with a mold that casts balls around .472", varying a thousandth either way depending on which direction I measured them.
You may notice if you look closely that the sprue hole isn't centered on the divide between the halves. Don't try to add and divide decimals in your head late in the day. I had to machine and file out the overhang on the deep side. The sprue looks wonky but the ball itself is fine.
My friend is going to try out the balls I cast and make some more if they work. The previous oblate spheroid ones from the uneven mold did group on the paper, but I was dissatisfied.
I borrowed 8-32 screws from a Lyman mold. I drilled and threaded the mold blocks so they can be used with standard handles. I made these handles out of some scrap.
