Bore Diameter For .650 Round Balls

[nkbj]

Starting out with .650" diameter round ball what bore diameter would you go with for a rifle?
I'm thinking .665" bore would be about right.
I'm wanting to go with progressive groove depth for paper patched minies.

The reason for asking is of course for looking into designing a barrel. In this case a barrel for some rather weighty hollow bases but that will also be used with .650" diameter round ball. And, I've found that in larger bores the gap between ball and bore needs to increase, such as shooting .562" ball in .577" & .580" barrels and .595" ball in a .61 bore rifle. The only bigger bore rifle I shoot is .696" and a whole different animal due to the extremely shallow three groove minie rifling.

What have you found with large bore round ball guns?
Has a ball diameter .015" under bore work for you?

This is going to be another long term put together worked in stages.

 

[cositrike]

Starting out with .650" diameter round ball what bore diameter would you go with for a rifle?
I'm thinking .665" bore would be about right.
I'm wanting to go with progressive groove depth for paper patched minies.

The reason for asking is of course for looking into designing a barrel. In this case a barrel for some rather weighty hollow bases but that will also be used with .650" diameter round ball. And, I've found that in larger bores the gap between ball and bore needs to increase, such as shooting .562" ball in .577" & .580" barrels and .595" ball in a .61 bore rifle. The only bigger bore rifle I shoot is .696" and a whole different animal due to the extremely shallow three groove minie rifling.

What have you found with large bore round ball guns?
Has a ball diameter .015" under bore work for you?

This is going to be another long term put together worked in stages.

Everything I shoot tends to like a ball about 10 thou smaller, with a 15-20 thou patch, but that’s just my experience. Others will differ and different barrels of the same caliber, may like a different patch, ball, powder combination, even by the same manufacturer. If I were you, I’d decide on a caliber. Make the barrel and then work out what ball it likes. Just my opinion..

 

[Tom Compton]

.660