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sprue up or down

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tom in nc

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All the round ball ammo I buy now seems to be forged rather than cast, so there are no sprues. However I still have a bunch that I bought years ago for my 1860 Colt replica that were cast. I've heard both ways sprue up and sprue down recommended over the years. I suppose aerodynamics is what makes the difference? Is accuracy affected? The advice I was given 50 years ago when I bought my first BP revolver was sprue down so that's what I've always done.
 
All the round ball ammo I buy now seems to be forged rather than cast, so there are no sprues. However I still have a bunch that I bought years ago for my 1860 Colt replica that were cast. I've heard both ways sprue up and sprue down recommended over the years. I suppose aerodynamics is what makes the difference? Is accuracy affected? The advice I was given 50 years ago when I bought my first BP revolver was sprue down so that's what I've always done.
Sprue up is easier to duplicate shot after shot
 
Sprue up so you can see it. I would bet the accuracy would be affected by the sprue being eccentric and forming an irregular, unbalanced projectile. If the sprue is up, one might be able to adjust if off center.
There is my $.02.
 
You can’t see if the sprues are centered if they are down.
Do you really think you are "centering" the sprue the same shot after shot by just "eyeballing" it. The gyroscopic force of the rifling spin pretty much negates any "off centering" of the sprue. So, whether it's up or down it just doesn't matter. I have yet to see any evidence, studies, or testing results to the contrary. It's just one of those "things" people believe one way or the other without any proof.
 
Don't make a damn bit of difference at the distances we shoot roundballs. At least from my testing. Davy Crockett could shoot the eye out of a turkey at 300 long paces with a ball cast from a bag mold and the sprue cut with nippers so what y'all worried about? Course he was usin' real black powder.
 
All the round ball ammo I buy now seems to be forged rather than cast, so there are no sprues. However I still have a bunch that I bought years ago for my 1860 Colt replica that were cast. I've heard both ways sprue up and sprue down recommended over the years. I suppose aerodynamics is what makes the difference? Is accuracy affected? The advice I was given 50 years ago when I bought my first BP revolver was sprue down so that's what I've always done.
I cast my own balls generally and the reason I prefer to load them sprue up is to better center the flat top where it can be seen. A cast ball will sometimes have a void in them from slag inclusions in the melt missed when skimming the dross and this will often cause a void some where usually under the sprue because this is the center of the molten lead pour flow.
A void off center in a bullet causes fliers and I am quite certain it doesn't do any good for the accuracy of a short waisted ball either.
It should be remembered that when a ball is loaded and then shot down a barrel it upsets and is no longer a true sphere but rather a short cylinder with a parallel sided waist engraved with rifling and two rounded ends which flies differently than a true sphere (golf ball).
The parallel sided waist with the rifling engraved in it is given a spin by the barrel traverse but also this imprinting creates drag like the feathers on and arrow which helps stabilize the spinning cylinder , with two rounded ends.
If a void is present in the projectile but is on center of spin axis then it will still fly true and the only variable will be trajectory because of weight difference which is why bullets and sometimes balls are weighed for target work..
 
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I've always figured it to be, like I said, a matter of air flow around the ball in flight. So, it seems the ball flying sprue first would have air flow problems? But then I've heard of shooters chewing lead balls (NOT ME) to intentionally make teeth marks on them. I think now-days shooters roll them between two files. Wouldn't that screw up the aerodynamics! Maybe I'm wrong and aerodynamics has nothing to do with it.
 
I've always figured it to be, like I said, a matter of air flow around the ball in flight. So, it seems the ball flying sprue first would have air flow problems? But then I've heard of shooters chewing lead balls (NOT ME) to intentionally make teeth marks on them. I think now-days shooters roll them between two files. Wouldn't that screw up the aerodynamics! Maybe I'm wrong and aerodynamics has nothing to do with it.
If I remember correctly a chewed ball is for smooth bore shooting and mainly to increase ball diameter some what, no? I don't shoot smooth bores so I'm asking .
 

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