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Lead balls have casting imperfections

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I load some pretty tight patched balls sprue up. After I whack the ball a few times with the short starter I can see that the sprue is pretty much flattened even before I ram it down the barrel with a range rod. Then the RB takes the force of a rearward explosion. I’d almost bet the sprue is the least thing in the entire equation that effects your accuracy.
 
But with the sprue up it contacts the wind first and off center a bit would it not create an off balance ball allowing it to exaggerate the lopsided spin and it to be effected and create a greater curveture in the arch of the roundball side to side? The pressure on the bottom of the ball would be the same virtually as the top of the ball thus push it out of line. The bottom of the ball is not in contact with the wind where as the top is and effected first and the most.
Well show me the difference in the groups you are talking about.
 
I every accuracy trial I have ever read, the base of the bullet is the most important. I always load the sprue up. I once shot a 10 shot table match with hand cast balls with a good sized sprue, that had an average of .210” spread. That was sprue up. The tremendous pressure on the base of the ball would push it out of line if the sprue was off center. That would have much more effect on accuracy than a slightly off center sprue on the front.
Thank you.

That post was the opposite of everything thing I ever read or experienced.
 
I have loaded my Sea Service flintlock pistols both sprue up and sprue down and there was no appreciable difference in accuracy at pistol ranges 20-30 yards. Just load with a snug lubed patch and have a ball shooting it.
 
Well show me the difference in the groups you are talking about.
I would but I can't tell you if it is the rb, sprue, wind, humidity and the biggest factor in the whole target results that has the most weight, me.......i thank you for not pointing out the major impact on my group is the over weight, going blind, jerker of the trigger, nut behind the butt. Me......
 
Sprue up, Sprue down, if you care about accuracy, Sprue Down. In the aerodynamics of the round ball, the "leading edge" needs to be as smooth as possible to cut down on flyers. The "trailing edge" is in a low pressure area, therefore any imperfections there will have less effect.
The thing that worries me about sprue-down is that you can't tell if the sprue is centered or not. If it's not centered, wouldn't that introduce a wobble in the trajectory (making it a slight spiral/helix pattern) due to the spin imparted by the rifling?

Granted, I haven't done any serious testing with this, but have had pretty fantastic accuracy with sprue-up.
 
The thing that worries me about sprue-down is that you can't tell if the sprue is centered or not. If it's not centered, wouldn't that introduce a wobble in the trajectory (making it a slight spiral/helix pattern) due to the spin imparted by the rifling?

Granted, I haven't done any serious testing with this, but have had pretty fantastic accuracy with sprue-up.
I see your point, but I've tested this and see a bit better accuracy with the sprue down. It's not much, but when shots count, you want every possible edge. The issue of a wobble from a helical spin will also happen with the sprue up if it's even slightly misaligned and it's going to be coupled with the issue of aerodynamics. Granted, the average plinker won't see it but if you're looking into eliminating all possible issues other than the nut behind the stock, then you'll be doing a lot of shooting and looking at any possible variable. My take on this is it's a minor variable, but does have an effect but probably of more issue is mass variation from casting. A 50cal ball that weighs just 2gr one way or the other has something that is going to really screw up accuracy.
 
Sprue up, Sprue down, if you care about accuracy, Sprue Down. In the aerodynamics of the round ball, the "leading edge" needs to be as smooth as possible to cut down on flyers. The "trailing edge" is in a low pressure area, therefore any imperfections there will have less effect.
That's a whole nuther subject of debate. I'm of the sprue up school.
 
Sprue up, Sprue down, if you care about accuracy, Sprue Down. In the aerodynamics of the round ball, the "leading edge" needs to be as smooth as possible to cut down on flyers. The "trailing edge" is in a low pressure area, therefore any imperfections there will have less effect.
Sprue down always made sense to me also. Aerodynamics considered. But there are many opinions recommending Sprue up. I guess I need to try both off a bench with all other variables constant to see the difference.
 
There is a whole lot of theory and opinion here with no documentation to back it up. I'd like to see some photos of groups with sprue up and sprue down shot with the same controlled conditions and equipment. Not that I doubt anyone but show us some proof. If I wasn't so lazy I'd do it myself.
Looking forward to the results of your tests
 
I always load patched round balls and my revolver bullets sprue up.

I figured the ramrod is going to mar the nose of the bullet anyway.

I have also always "heard" that the tail end of the bullet is the most crucial part for flying true, so I figure an unmarred "tail" would be best.

But I never did any load workups one way or the other way to test.
 
There is a whole lot of theory and opinion here with no documentation to back it up. I'd like to see some photos of groups with sprue up and sprue down shot with the same controlled conditions and equipment. Not that I doubt anyone but show us some proof. If I wasn't so lazy I'd do it myself.
Looking forward to the results of your tests

You might be looking for quite awhile!:)
 

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