Load Shoots to the right

[James Stella]

I am working on a round ball load for a 12 gauge Fowler. I started with a .690 lead round ball and a .20 patch. At 50 yards the load shoots center but a little low. Then I switched to a .690 round ball cast from bismuth and the same patch. The elevation is about the same but for some reason it shoots about 10” to the right at 50 yards.

Does anyone have any thoughts on what would cause it to shoot to the right?

I expected some elevation change because the bismuth is lighter. I did not expect the drastic windage change.

 

[William Lincoln]

Those barrels are regulated with bore lasers or lead tests if a SXS , if Single barrel
then try increasing the load in a graduated fashion. Higher charges act like greater
mass in the projectile. Try a heavier charge before fiddling around.

 

[James Stella]

Those barrels are regulated with bore lasers or lead tests if a SXS , if Single barrel
then try increasing the load in a graduated fashion. Higher charges act like greater
mass in the projectile. Try a heavier charge before fiddling around.

It is a single barrel. Ok I will try to up the charge tomorrow morning and see what happens. Thank you.

 

[Britsmoothy]

It's leaving the barrel whilst it is in a different phase of recoil. Was you bench shooting or standing?

 

[Brokennock]

Wind? Was there a crossing wind at the range that day? The lighter ball will be more greatly effected by wind.
Also, being cast of a different material, which acts differently than lead when cooling, is the diameter the same? Should you adjust patch thickness to try to achieve the same amount of tightness in the bore as the patched lead ball?

 

[James Stella]

It's leaving the barrel whilst it is in a different phase of recoil. Was you bench shooting or standing?

I was on a solid bench with sandbags.

The different phase of recoil is an interesting thought. So just to add to it a bit more I was shooting with a friend who was shooting a 50 cal flintlock rifle. He was shooting at 100 yards. His lead balls were hitting the bullseye. His bismuth balls were also striking left. Not as far left, about 6” at 100 while I was about 10” at fifty. But I was shooting a much larger projectile.

There was no wind. Very calm.

 

[James Stella]

Wind? Was there a crossing wind at the range that day? The lighter ball will be more greatly effected by wind.
Also, being cast of a different material, which acts differently than lead when cooling, is the diameter the same? Should you adjust patch thickness to try to achieve the same amount of tightness in the bore as the patched lead ball?

So it was very calm and I was on a bench so wind would not have been it.

But you are right on with the diameter. So the lead balls are .690. The bismuth are about .694. I used the same .020 patch. It was a much tighter fit. I thought that was a good thing but maybe not.

 

[Britsmoothy]

Try off hand.

 

[Brokennock]

So it was very calm and I was on a bench so wind would not have been it.

But you are right on with the diameter. So the lead balls are .690. The bismuth are about .694. I used the same .020 patch. It was a much tighter fit. I thought that was a good thing but maybe not.

I have often found with my smoothbores that unlike rifles, tighter is not always better. Try a .015 or even .010 patch.
Or try loading; powder, thin card, lubed wad of some type, ball, thin card.

 

[mushka]

You changed the ball dynamics when you went to bismuth so the point of impact naturally changed. Different materials do different things.

 

[James Stella]

You changed the ball dynamics when you went to bismuth so the point of impact naturally changed. Different materials do different things.

I expected an elevation change but not the huge windage change. I need to find a way to bring it more center. Going to play with different patch thickness and an over powder card.

 

[James Stella]

"Brokennock

I will try the different patch thickness and an over powder wad. Thank you.

 

[James Stella]

On the plus side this is a 25 yard pattern using 1 3/8 of #5 bismuth over 89 grains of ffg. A nitro over powder wad and on overshot card.

 

[William Lincoln]

That's a great pattern for 25 yds. Try 100grs for the 50 yds and adjust as for windage
slightly. Watch for tensing or flinching.