Round Ball Tumbling With Graphite

[Pro Libertate]

It was suggested on a bullet casting forum that I try putting a squirt of dry graphite in with my round balls and allow them to tumble in a rock tumbler for a few hours. I opted to let these go overnight. During the casting process, some of my bullets ended up less than perfect, with small divots, casting and sprue marks left by the Lyman mold. This method resulted in balls that were perfectly round, with a shiny, hammered finish appearance. Give it a try— I think you’ll be most pleased with the results!

 

[LME]

It was suggested on a bullet casting forum that I try putting a squirt of dry graphite in with my round balls and allow them to tumble in a rock tumbler for a few hours. I opted to let these go overnight. During the casting process, some of my bullets ended up less than perfect, with small divots, casting and sprue marks left by the Lyman mold. This method resulted in balls that were perfectly round, with a shiny, hammered finish appearance. Give it a try— I think you’ll be most pleased with the results!

View attachment 310331View attachment 310330View attachment 310332View attachment 310333

 

[longcruise]

Not sure what the graphite is for but it did a good job.

I don't have a tumbler but do have a vibrating case cleaner. By removing the media and putting a layer of balls in the bottom they come out nicely in a few hours. However, if any reading decide to do the vibrator be sure not to stack layers. They need to be able to roll around. Stacking gives up flat spots.

 

[Pro Libertate]

Not sure what the graphite is for but it did a good job.

I believe the graphite kind of amalgamates with the lead dust and helps it to settle. I’ve read that graphite used to be used to line cannons and resulted in better lubricity of the bore. When rolling the ball between my fingertips, it feels substantially slicker to the touch than the untumbled balls, which may owe to the graphite or simply the polishing action of being tumbled. The balls have taken on this obsidian color and almost appear as though they’re magnetite, although -oddly enough- they don’t leave any black residue on your hands when handled.

 

[longcruise]

Interesting! I'm going to try the graphite. What is the spray you use.

 

[Pro Libertate]

Interesting! I'm going to try the graphite. What is the spray you use.

This is what I use; the bottle must be 20-something years old, as I’ve had it for about as long as I can remember. I’ve heard that chunks of pencil lead will also work.

 

[longcruise]

Thanks. I've seen that in the hardware store.

 

[deerstalkert]

looks nice, how do they shoot in comparison to un tumbled?

 

[Pro Libertate]

looks nice, how do they shoot in comparison to un tumbled?

I’ll have to get back with you on that. I was planning to shoot Brown Bess today but Mother Nature just laughed and sent copious amounts of rain.

 

[ZUG]

Interesting stuff here - Keep us posted on how this is working out for you.

 

[Urban Coyote]

I'm thinking it wouldn’t correct visible casting imperfections but might hide them.

 

[Pro Libertate]

Interesting stuff here - Keep us posted on how this is working out for you.

I sure will! Tomorrow’s forecast is a little nicer, so I’m hoping to get out there and put some lead pills down range.

 

[Pro Libertate]

I'm thinking it wouldn’t correct visible casting imperfections but might hide them.

I could see where if you had deep fissures throughout your round balls that you’d be better off simply returning ‘em to the sprue pile and back into the pot as opposed to trying to obfuscate what could be accuracy-robbing imperfections. But for minute blemishes? If I can turn a round ball over in my palm and can’t discern where a sprue or fault once was, that’s good enough for me! I think they’re every bit as perfectly spherical as any Hornady/Speer ball I’ve ever seen.

 

[NotDanielBoone]

It was suggested on a bullet casting forum that I try putting a squirt of dry graphite in with my round balls and allow them to tumble in a rock tumbler for a few hours. I opted to let these go overnight. During the casting process, some of my bullets ended up less than perfect, with small divots, casting and sprue marks left by the Lyman mold. This method resulted in balls that were perfectly round, with a shiny, hammered finish appearance. Give it a try— I think you’ll be most pleased with the results!

View attachment 310331View attachment 310330View attachment 310332View attachment 310333

Has this improved your groups? and how much.

 

[2 shots]

imagine what these balls would do with a silk patch...

 

[Chief Snorkel]

I dry tumbled my last batch. All imperfections were gone, and uniformity of weight was very close. They shot very well.

 

[Pro Libertate]

imagine what these balls would do with a silk patch...

Too rich for my blood!

 

[deerstalkert]

imagine what these balls would do with a silk patch...

better yet, teflon tape patch!

 

[Pro Libertate]

better yet, teflon tape patch!

We’ll now you’re just being silly!

The patch doesn’t stay with the ball the whole length of the barrel during firing, so I should think there’s plenty of opportunity for the ball’s lubricity to affect velocity. Even if this increase in speed is slight, who doesn’t want to achieve the most velocity they possibly can?

I’ve read that cannon barrels were once lined with graphite to improve ease of loading, but mine is only a theory. Using a chronograph on untumbled round balls versus tumbled without graphite and finally tumbled with graphite ought to settle any debate.

 

[Beaverman2]

I've been tumbling dry in a HF rock tumbler for years, works great, from the bench they shoot tighter groups than not tumbled.