Ball size for .40 caliber?

I saw some roundballs for sale on the forum here. They are .389". Would these be the right size for my .40 caliber flintlock?

Jim

Yes. They may be handcast and that it how they measure. Moulds are available for .400, .395, .390 and .380 that I know of. I have chronographed .400, .395 and .390 balls with the same load in one rifle and there is little difference in velocity or accuracy with them.

Thanks. At only $5 for 100 balls I might as well buy them all. I just wanted to be sure these weren't for a pistol and find that I needed .395" for my rifle.

Jim

You might want to check the hardness of those balls with your thumbnail. If you can put a groove in them they are pure lead. If you can't they probably are some sort of alloy.

IMO, at that price, even a moderatly hard alloy would be a good deal. You may have to use slightly thinner patches though.

Zonie- thinner patches? With a .389" ball I thought I would need a thicker patch.
I haven't bought the balls yet. They look to be commercial roundballs, made by Rush Creek Roundball.

Jim

IMO, a thousandth of an inch, give or take won't make much difference.

As I'm sure you know, a general rule of thumb is to size a soft lead ball .010 under the guns bore size and then patch it while loading.

Using your .40 caliber rifle, that would make the recommended size somewhere around .390. .389 is only .001 smaller. That's about 1/3 of the thickness of one human hair.

The reason I mentioned thinner patches is some folks have found that if the ball is cast out of a hard lead it will be harder to load with patches that work well with soft lead.
By using slightly thinner patches when used with a hard lead ball it's easier to load and often not much accuracy is lost.

Rush Creek casts good balls. Chuck Dixon sells them at his store, too. They are pure lead, not an alloy. Most .40 cal. guns will shoot the .390 ball quite well, using a .015" thick patch material.

Thanks Zonie. It makes sense now.
Since paul said the Rush creek balls are good to go it looks like I have too much of my money.

Jim

Been thinking about trying to get the .380" to work seeing as I use them in the .36 Navy. But, been outa town on business for a week and it's hard to find time to do important stuff.

The .380 balls will work very well in a .40 caliber rifle. I've shot a lot of them. Lee has a double cavity mould for the .380

These are .389", not sure about your .380". Since they are the correct size and a good price I told the seller I would take all of them. 6 boxes of 100 = fun!

Jim

Just to confuse matters, I have an old Dixie Cub percussion in 40 caliber. I get best results with .400 round ball and a .015 patch. The rifling isn't worn, that's just the size that works in that particular rifle. But chances are your bargain ammo will work just fine.

Jeff