Size Round Ball for a Muzzleloading Rifle

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quillgordo

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Hi
I know trial and error is the best method. But my question to all knowledgeable is this. In choosing an initial size for a round ball, is it correct to state that the round ball should drop all the way down the barrel without a patch? Then picking the proper patch thickness is the determiner of accuracy?
 

Grenadier1758

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Trial and error is one method, but is it the best?

I wouldn't feel it is a correct method to drop a ball down the barrel to see if it falls to the breech. A ball may drop all the way to the breech and not come out if there is some oils or fouling at the breech and now you have to find the ball puller or CO2 discharger to remove it.

The best approach is to measure the barrel and determine the bore diameter at the lands. Measure to the bottom of the grooves too. The starting ball should be 0.010" less than the land to land diameter for a relatively easy load or 0.005" for a tight load.
 

Kansas Jake

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I've taken the easy way with mine and just started with the common ball size if it is a common caliber. In other words, a .490 for a 50 or a .440 for a 45. Cap and ball revolvers are a little trickier as the same caliber may work better with one size or another. Having said that, I've had good luck with .454 in 44 calibers for the most part. Several work fine with .451s and in a couple that is almost too small. Rugers need .457 according to most here.

Grenadier has the best advice to start out, but when I got in this game many years ago I didn't have a caliper and the cheap Harbor Freight stuff wasn't an option.
 

hanshi

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What they said! Start with a ball .010" under caliber - you can also use a ball .005" under bore diameter. I shoot tight loads but not everyone does.
 

Grenadier1758

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When you have production guns or barrels from known manufacturers, going 0.010" or 0.005" under the published spec is a reasonable approach to selecting ball size. However I have bought several guns that don't have marked caliber on the barrel. My T. Strubel flintlock pistol being one and other measures have to be adopted. What will happen to all those T/C barrels sent off to Bobby Hoyt and now they are some other caliber than the one stamped on the barrel. Then there are those coned barrels that will be much larger at the muzzle than further down the barrel.

I inherited my tool maker father's tools, I have all the calipers, micrometers, telescoping gauges and ball gauges, so measuring bores was not much of a problem. I do understand that such measurements can be a problem for some. Well, that's why we are on these boards to try to help as best we can.

A trial and error approach can work with an assortment of balls of different diameters. Drill a hole through the ball and insert a bolt and a nut to hold the ball on the bolt. the long threaded end can be pulled up to remove the ball. When you have a good slip fit and little side play you can try loading the bolt and ball with a patch to see how that feels. Now you have a starting point for load development. Pin gauges are another choice, but can be expensive. A set of drill bits can be used for an approximate size, but they are not exact enough to determine if you need a ball 0.005" different. And if the bore is larger than 0.500" drill bits aren't the best option. There are those tapered bore gauges that can help but they are not exact enough either.
 

quillgordo

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When you have production guns or barrels from known manufacturers, going 0.010" or 0.005" under the published spec is a reasonable approach to selecting ball size. However I have bought several guns that don't have marked caliber on the barrel. My T. Strubel flintlock pistol being one and other measures have to be adopted. What will happen to all those T/C barrels sent off to Bobby Hoyt and now they are some other caliber than the one stamped on the barrel. Then there are those coned barrels that will be much larger at the muzzle than further down the barrel.

I inherited my tool maker father's tools, I have all the calipers, micrometers, telescoping gauges and ball gauges, so measuring bores was not much of a problem. I do understand that such measurements can be a problem for some. Well, that's why we are on these boards to try to help as best we can.

A trial and error approach can work with an assortment of balls of different diameters. Drill a hole through the ball and insert a bolt and a nut to hold the ball on the bolt. the long threaded end can be pulled up to remove the ball. When you have a good slip fit and little side play you can try loading the bolt and ball with a patch to see how that feels. Now you have a starting point for load development. Pin gauges are another choice, but can be expensive. A set of drill bits can be used for an approximate size, but they are not exact enough to determine if you need a ball 0.005" different. And if the bore is larger than 0.500" drill bits aren't the best option. There are those tapered bore gauges that can help but they are not exact enough either.
Yes! I have an unmarked barrel. 451 ball sits on the crown right about at the center of the ball but will not go down the barrel. This I am thinking is too large a ball the .440 will drop down the barrel and does need some force with a .0010 patch therefore this must be the proper ball. Agree???
 

mooman76

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Try it and see. It's the only way to tell for sure. Some guns like a tight patch and some do fine with a patch that is just snug. Depends on your loads too. If you plan on heavy loads, you might need a heavier patch.
 

Grenadier1758

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Yes! I have an unmarked barrel. 451 ball sits on the crown right about at the center of the ball but will not go down the barrel. This I am thinking is too large a ball the .440 will drop down the barrel and does need some force with a .0010 patch therefore this must be the proper ball. Agree???
I agree on the 0.440" ball, but the one thousandths patch (I know you meant 10 thousandths) is too thin. For that 0.010" may be too thin and 0.015" or 0.018" may be a better if tighter loading choice.
 

SDSmlf

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Yes! I have an unmarked barrel. 451 ball sits on the crown right about at the center of the ball but will not go down the barrel. This I am thinking is too large a ball the .440 will drop down the barrel and does need some force with a .0010 patch therefore this must be the proper ball. Agree???
Maybe. Do you want to measure the bore diameter? For one simple method you will need a small piece of brass or copper rod, maybe 3/8” in diameter by 6” to 12” or so long. Put can rod down the bore and follow it with that .451” ball down the bore a few inches, driving it those few inches with another short piece of the brass/copper rod. Then let the rod behind the ball work like a slide hammer by raising and lowering the muzzle. When that resized .451” ball finally comes out you will have a slug the size or your bore that you can measure.

Personally I start with a patch and ball combination where the ball and compressed patch material fill the bore and the grooves. Ball is typically .010” under bore size. For example, assume you have a .450” bore with .008” deep rifling. That means you are filling a .466” rifling diameter. With a .440” ball you would want .013” thick compressed patch material. All bores are different, but this is what works for me as starting point.
 

quillgordo

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Ok using dial calipers I measured the barrel diameter which is .445. The groove diameter will go as high as .475 and grooves appear to be directly across from one another since there are 8. but it is unreasonable to assume I am exactly 180 degrees, so probably somewhere less than .475 this is appx 30/1000's so it looks like a .440 round ball leaves between 30 to 35/1000 room so I will try .010 and .015 patches and see what is best accuracy. I will update. Thanks
 

Sidney Smith

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If you choose a ball that is ten thousands under sized and with the proper patch reasonable force is required to ram it home then you've probably got the right combination. A setup that requires excessive force may work for the first shot on a clean bore but will most likely get stuck after 2 shots, then that is too much. Any setup that requires a hammer is way way too tight and should not be used period.
 

Rifleman1776

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A simple approach that has worked for me is to choose two sizes of balls you believe might be right for your rifle. e.g. a factory made .45 might want a .440" or .445" ball. Using a large hunk of the patch cloth you plan to use, short start the small ball into the bore. Then pull it out and examine. It may, or may not, have rifling and patch weave impressed into it. Then do same with the larger ball. You want a ball/patch combo that grips he rifling firmly but is not too difficult to start and seat. Whichever one you like best, try shooting that from rest to learn if it groups OK or not.
 

tenngun

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I have never slugged and miched a barrel.
Several companies sell cast ball in multi sized. I buy a few bags and see which one works best.
As a teen I bought my first gun patches and ball, a measure and powder. The gun shop owner told me I needed 70 grains and a patch around the ball and rammed home.
He was in his sixties was born in the 19teens. And grew up with an ml as a boys gun. Unlike many folks you might find in a shop today he knew how to load one.
I found it hard to start the ball and Invented the short starter.
I was a little late to get a patent.
Ok, before about 1850 we have almost zero evidence of my great invention.
That means men stated ball with a tap( sometimes with a knife handle) then brut strength.
Round about story to get to my point. On you tube there is a fun channel called the Black Powder Maniac. He shoots a .50
Most shoot a .490,.495.497 or a .500 and different patch thickness.
Trying to keep in old style lots of folks don’t use a starter, and Black powder Maniac one of these boys. By dropping his ball sizes and using a thick patch he gets a good fit with out Putting too much stress on his rod or his wrist. He shoots a .485 ball.
Often in old guns we see smaller ball used in rifles then what’s common today.
Just going with a number won’t always give you the best you need.
 

hanshi

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Decades ago when my hands were strong and didn't hurt I'd simply use the ramrod to both start the ball and seat it. Can't do that now. Especially since I shoot tight loads a short starter is mandatory.

Here's some results of a bit of "paper figuring" with a .45 rifle I shoot: bore; .450" + .024" grooves = .4740". .440" ball + .046" patch (.023" + .023") = .4860" prb - .4740" gives .012" compression in the grooves.

Now with a .445" ball + .046" (.023" + .023") patch = .4910" prb - .4740" = .017" compression in the grooves.

This is a moderately tight load with both the .440" ball and the .445" ball, and the balls are interchangeable and safely seated with the wood ramrod. Bore stays clean - well, as clean as BP allows - and NO wiping is needed until shooting is over and it's time to go home. Best of all the accuracy does not suffer. This pretty much goes for every caliber I shoot. If my math is in error I'm sure it will be pointed out by someone better than me.
 

Cattman

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i use a round ball 5 thousands smaller that the top of the lands bore. i use medium weight tight weave pure linen patches cut off at the muzzle. you cant get better for accuracy than that. i shoot in mostly open country so some shoot can be at least 150 yards or more. if i hunted in the woods like many do here and shots were 20 to 75 yards i could get by with less strictness in loading my round ball side lock. out here you need long range accuracy.
 

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