Target shooting. Roundball .440 vs .445

[stephenprops1]

I have a 45 caliber Pedersoli Missouri River Hawken rifle. Thru trial and error, I have gotten the best accuracy, target shooting, with a .445 round ball, .012 patch, and 40 grains of Goex FFF.

 

[davesonic4444]

I recently purchased a 45 DGW flintlock and hope it likes the same 445 balls i shoot now. I have 440 as well to try. My trial will be my Green Mountain barrel for comparison.

 

[Jay Templin]

A lead ball will expand to fill the grooves.

Will a lead ball expand to fill the grooves? I thought that’s what our patches were for. I’ve never seen rifling marks on any of the roundballs I’ve recovered.
I shoot both .440 and .445 in my .45 with no discernible difference in accuracy. I suspect that has as much to do with my marksmanship (or lack thereof) as with the fit of the balls.
Jay

 

[bpd303]

Could mean the patch material is weak and of low quality. Not performing it's function.

That was the problem when I was testing the 50 cal Charlie Caywood SMR. Very old .010 Wonder Lube patches, that disintegrated with a 490 RB. Have I said how much I dislike Wonder lube? I switched to .010 cotton patches and Stumpy's Moose juice lube, a world of difference in accuracy but still trying other things.

 

[Grenadier1758]

Here's my initial calculations for determining the patch thickness for a given round ball and barrel.

The original poster for my reply had a rifle with a bore of 0.451" diameter land-to-land.

Let's take that 0.451" bore and look at fitting that 0.445" ball. We have (0.451-0.445) 0.006"/2 or 0.003" of windage between the ball and the lands. If the patch material is 0.012" compressed or 0.018" uncompressed. we have two thicknesses of patching that go between the ball and the bottom of the groove or 0.445 + 0.018*2 (Ball and patch of 0.481" before compression into the barrel). The patch material is going to displace some of the soft lead ball as the patch is compressed in the 0.003" between the lands and the ball. If the grooves are 0.010" deep, the 0.018" patch is getting compressed to 0.013". That's enough compression to lightly impress the patch groove location onto the ball and with patch lubrication effectively seal the barrel. Well, never perfectly, but adequately. Yes, it takes a good sharp rap with the short starter to get the ball and patch into the muzzle. Once the lead ball is impressed into the patch at the lands and in the groove, the ramrod can push the ball and patch to the breech.

I have consistently had good results with using the cotton drill #40 from JoAnn's Fabrics (0.018" thick uncompressed and 0.014" compressed). Yes, I have heard that JoAnn's Fabrics has applied for bankruptcy. So far they are planning to remain in operation while they reorganize.

 

[davesonic4444]

Thanks for everyone's interest in my topic! Whenever i reach a conclusion i will post my results.
Dave

 

[Pete G]

In general, a tighter ball/patch combo will be more accurate, but there are exceptions.