Well, I finally got around to making a couple of new moulds ~ one for a Nessler Ball and one for a ribbed hollow base slug.
For those not familiar with the Nessler Ball, it was developed in about the middle of the 1800's by a Belgian fellow and was intended to replace round balls in smoothbore muskets. It was designed similar to a Minie in that it is undersize for the bore so allows for fouling and was reputed to increase both accuracy and range. I can buy the improved accuracy if it behaves like a Foster slug (shuttlecock design) and doesn't tumble ~ round balls pick up random spins after a bit of travel then tend to veer off target like a curve ball. As for increased range, I cannot see how such a stubby little slug would be any more aerodynamic than a round ball.
I had read about Nessler balls several years ago and had wondered about the claims of improved accuracy and trajectory. They were used by several European countries and played a large part in the Crimean war and were also used in the American Civil War so must had had something going for them. However, they were quickly displaced by the Minie Ball and rifled guns.
I had found some pictures of Russian Nesslers and so traced and scaled one then 3D modeled it to get drawings and make a mould. However, I recently found a dimensioned drawing:
So used that to model then scaled up to 0.729" from 0.677". If it works out then the original size would be a good wad slug and weighs about 460 grs. in pure lead.
I also wanted to try another hollow base design more or less like the turbo design bikerbeans is using so modified my ribbed slug mould (Brenneke like) to a similar proportion. Not quite sure why I went with ribs instead of smooth but that's what I did. It has a good forward balance point and fairly thick nose.
The ribbed slugs didn't cast as well as hoped due to slightly cool mould then when it warmed up enough the skirts started cracking. It needs a wee bit more release angle to ease out of the mould. I have made a different version of this and finned slugs as well successfully in the past so I will get that sorted out shortly.
Here's a photo of the two new slugs waiting to be tested:
I cast up 20 of the Nesslers and 12 or 15 ribbed slugs to test before I had ejection problems.
The Nessler is about as close as I could make it and it came out pretty well. No, I have no idea why the weird little tit is in the middle. It weighs 550 grs.
The ribbed slug comes in at 520 grs.
While I wouldn't have expected it the Nessler balances right about where the ogive ends at the little shoulder. I made a push out mould so use a nose form which leaves a very small shoulder. Otherwise it is very close to the Nessler drawing. I hear good reports of the Lee 7/8 oz. slug accuracy and it is short and stubby so maybe this little guy has a chance. We'll see.
Testing will hopefully happen by next weekend (not this coming weekend). Wish me luck!
Longbow