How to make a mold for a breneke slug?

[Y-man]

BUMP! Anyone hear from Otonel after this?

[longbow]

Well, there's a blast from the past!

No, I haven't seen any posts from Otonel after that.

He did some good work. I wonder how well they shot?

Longbow

[country gent]

I think the slug could be cast in a cylindrical style mould but slightly different. would need to be made as a nose pour mould to get the nose. body would be the ribbed section and base ring dia out the bottom and a removeable plug with pin for hole and the ring cut out that's locates and locks in place at a set depth. In use heat mould base insert up and fill with lead. Cut sprue and remove base pin. with a dedicated nose punch drive bullet out the bottom. Would be a slow operation compared to regular moulds.

The problems is as a base pour the groove and hole cant be cast into the base, and the drive ring ribs become a mechanical lock into the mould. The slug could be cast as a round slug at base dia of the ribs with nose and base then the ribs swaged on shortening the slug due to the material moving into the ribs. The above mould is going to take some interesting machining for several reasons. The angled ribs flow around the radious so they cant be cut easily and maintain the true round shape. They also need to be cut in at the exact location since they also wont allow for you to lapp the mould to final size. Keeping the base pin hot while doing the operations is going to be hard as it will be slower. Another option is a small arhbor press with the ejector mounted in the ram so mould can be set in it and the bullet pushed out not hammered out. This would speed up the process some. A L type handle on the base pin may help and would allow for pin to be hung in pot in the lead helping to keep it hot also. This handle will need to be "timed" to handle location also.