Bag style ball mold, size increase?

[Brokennock]

The recent thread from @Canute Rex on his successful manufacture of a ball mold, and the reply from @necchi prompt me to ask a question I've wondered about before.
Could an existing inexpensive bag style mold have its cavity size increased, economically, by someone with the skills @Canute Rex has demonstrated?

Can it be done for less than the cost of a new Callaghan mold?

 

[rich pierce]

The recent thread from @Canute Rex on his successful manufacture of a ball mold, and the reply from @necchi prompt me to ask a question I've wondered about before.
Could an existing inexpensive bag style mold have its cavity size increased, economically, by someone with the skills @Canute Rex has demonstrated?

Can it be done for less than the cost of a new Callaghan mold?

If a few thousandths, maybe a couple calibers, should be no problem. I’m not sure if he uses different sized blocks for large and small calibers.

I like Larry’s molds but for competition I’d prefer the type with an integral spruce cutter. I’m not sure there’s an accuracy difference but gnawing the spruce off is invariably uneven with Larry’s molds. I still use them for plinking, hunting, and woods walks.

 

[Brokennock]

If a few thousandths, maybe a couple calibers, should be no problem. I’m not sure if he uses different sized blocks for large and small calibers.

I like Larry’s molds but for competition I’d prefer the type with an integral spruce cutter. I’m not sure there’s an accuracy difference but gnawing the spruce off is invariably uneven with Larry’s molds. I still use them for plinking, hunting, and woods walks.

I don't have one of Larry's molds yet.
And really can't afford one anytime in the foreseeable future.
I have one of the cheap bag style molds from Track Of The Wolf in a .600 size, but shoot a lot more .610 ball than .600 from both guns. I have a Lyman .610 but would like to have a bag mold that size.

 

[Canute Rex]

If you wanted to increase the cavity size of a ball mold you'd need one of three setups.

1) a lathe with a four-jaw chuck and a ball end cutter of the exact size for the desired ball. The first is not hard to find but the second is tricky, given that ball end mills are not produced in convenient sizes for muzzle loading firearms.

2) a lathe with a four jaw chuck and a ball/cavity cutting tool. It's an adjustable cutter on a pivot that can cut convex or concave hemispheres or spheres. You could either cut out the interior of the mold cavity or cut a mold cherry. I'd probably go for the mold cherry so I could screw it up a few times without ruining the mold.

3) A blacksmith's shop, a piece of steel plate, a steel rod, a tapered reamer, and the ability to forge, true, and case harden a cherry. I plan to do this exercise at some point for my own perverse amusement.

 

[Brokennock]

If you wanted to increase the cavity size of a ball mold you'd need one of three setups.

1) a lathe with a four-jaw chuck and a ball end cutter of the exact size for the desired ball. The first is not hard to find but the second is tricky, given that ball end mills are not produced in convenient sizes for muzzle loading firearms.

2) a lathe with a four jaw chuck and a ball/cavity cutting tool. It's an adjustable cutter on a pivot that can cut convex or concave hemispheres or spheres. You could either cut out the interior of the mold cavity or cut a mold cherry. I'd probably go for the mold cherry so I could screw it up a few times without ruining the mold.

3) A blacksmith's shop, a piece of steel plate, a steel rod, a tapered reamer, and the ability to forge, true, and case harden a cherry. I plan to do this exercise at some point for my own perverse amusement.

Thanks.
Option 3 is out for sure.... at least for me personally and the only friend I have that could possibly pull it off lives almost 10 hours away.
But I'm definitely hoping you try it and post on it.

If one were to try option 2, how does one cut the teeth into the cherry?
Option 1 sounds best, but for the size issue regarding ball end cutters. Would need .610 and .595
What are some sources to check?

 

[DixieTexian]

Wouldn't you need to make it slightly oversize to account for shrinkage?

 

[tenngun]

I can’t say enough good about Larry’s molds. They make pretty much all the ball I use. Save your pennies but cause his stuff is worth every cent. And since he didn’t make as big as I needed for my new eleven bore I had to buy a Lyman, and handles and mold was a lot more then Larry’s

 

[Canute Rex]

Thanks.
Option 3 is out for sure.... at least for me personally and the only friend I have that could possibly pull it off lives almost 10 hours away.
But I'm definitely hoping you try it and post on it.

If one were to try option 2, how does one cut the teeth into the cherry?
Option 1 sounds best, but for the size issue regarding ball end cutters. Would need .610 and .595
What are some sources to check?

.610 is very close to 39/64". .595 is very close to 19/32". You can get a ball end mill in that size, but it will cost you about $60. Not something to do unless you have a profound attachment to the mold you have. A ball/hemisphere cutting jig will cost $100 or more, and then you have to learn how to use it.

It would be cheaper and easier to go to Larry and just order one up.