Sprue cut: Facing which way?

[deerstalkert]

sprue up only as a way to center. up down really doesn't seem to matter to me. side ways only seems to make it a tad more difficult to get down the bore. never heard it go wooo woooo down range after being fired

 

[hanshi]

Sprue up for me, too. Lee molds don't leave a sprue on the ball, so that's not a problem there. Most other molds do leave them and tumbling doesn't always do away with them completely. Sprue up lets me see if the ball is truly centered.

 

[sheriff john]

up

 

[oldwood]

In the early 1980's every sport store sold sprueless round balls. I had no time back then to cast round balls , but still wanted to shoot as much as I could. I found no difference between shooting sprueless balls vs. cast balls w/ sprues. Was shooting a Getz T/F 44" .50 cal . , round bottom grooves , .490 ball , 80gr. FFFG Can't remember patch thickness. Was using mutton fat lube (Old Zip) , until the Pink jojoba lube , was on sale.

 

[tom_in_vt]

I always load sprue up…

 

[appalichian hunter]

There was a article a few years back in muzzle blasts, I believe bye the writers who went bye the name of the bevel brothers about this, I load sprue up if I run ball, if shooting factory ball I buy swaged balls. Really do not see where it makes all that much difference as long as you center the spru in the patch.

 

[FPDoc]

I just deleted two well thought out and nicely worded posts that each took some time to compose. The 2nd was a bit snarkier than the first. Pretty much decided though that beyond powder first.. then the ball, it's sorta personal preference. Thought you'd like to know.
Oh.. I do load sprue up cause that's what an old guy told me to do. ;-)

 

[RAEDWALD]

Spruce up lets you centre the ball better but a cast ball has a void below the spruce so sprue down has the heavier end flying at the front end. The British army thought that it was worth the (then) large expense of going over to swedged/swaged ball production instead of cast balls.

 

[Billy Boy]

Relatively new to the sport but (though decades with smokeless) I have been shooting and having a blast. Really haven’t tried for super duper accuracy yet and just having fun. As my smoothbores are replicas of military weapons I have been using paper cartridges so far.

Before I even rolled my first cartridge I had presumed the flat of the roundball (sprue cut) should be “down” facing the powder. This made sense to me as the outhouse expert on ballistics. Then read from a current “well known” source that the flat should be centered “up” toward the muzzle and have been loading and shooting that way.
Just read a book from the apparent grandfather of the sport (Sam Fadala) who flips the apparent current thinking and states the flat should be facing the powder.

Do we have any real science or thorough testing on which way the ball flat should be facing? Up or down?

Easier to see if it is centered if the sprue is up, seating it may flatten it slightly.

 

[toot]

I would rather have it going out of the barrel facing to the rear than to the front, why? less resistance to the affects of the atmosphere / wind going against it. sort of acts ack's like a tail. jmho.

 

[Whughett]

Off thread but related: Lee advertising indicates that their sizing method of pushing a bullet thru the sizing die nose first, force is applied to the base of the bullet, is superior to the Lyman/RCBS method of pushing it into the size die base first, force is applied to the nose.
Reason any deformation of the nose contributes to loss of accuracy. A sprue or mark of a sprue would be a deformity.
Just a bit of trivia.

 

[Loyalist Dave]

"Next place a ball, with the sprue up, [author's emphasis] in the center of the patch..., "

"I have heard old riflemen, years ago, say that it mattered not whether the sprue surface of the ball is placed at the bottom or the top when loading the round ball rifle, but this is not reasonable, and does not agree with my experience and that of the majority of the experienced riflemen who shoot the muzzle-loading rifles. ..., Experienced experts agree that better accuracy with the round ball rifles will be secured by always loading the sprue surface of the ball at the top, [author's emphasis] or towards the muzzle."
Ned Roberts The Muzzle-Loading Cap Lock Rifle (1947)

LD

 

[Grenadier1758]

In the early 1980's every sport store sold sprueless round balls. I had no time back then to cast round balls , but still wanted to shoot as much as I could. I found no difference between shooting sprueless balls vs. cast balls w/ sprues. Was shooting a Getz T/F 44" .50 cal . , round bottom grooves , .490 ball , 80gr. FFFG Can't remember patch thickness. Was using mutton fat lube (Old Zip) , until the Pink jojoba lube , was on sale.

The sporting goods stores still do sell round balls that do not have a sprue. The Speer and Hornady swaged balls are formed in a spherical cavity that presses the soft lead into a sprueless round ball.

 

[Brokennock]

The sporting goods stores still do sell round balls that do not have a sprue. The Speer and Hornady swaged balls are formed in a spherical cavity that presses the soft lead into a sprueless round ball.

True. But sizes are limited and cost is a factor, also one is then beholden to a store.
But it is a good place to start for newcomers or those trying to determine what size mold to get.

 

[Grenadier1758]

True, @Brokennock, not only are the sizes limited but quantities of the swaged round balls are limited. Even major distributors such as Grafs and Midway USA are sold out of some sizes. Then the round ball molds have become scarce.

 

[smoothshooter]

Relatively new to the sport but (though decades with smokeless) I have been shooting and having a blast. Really haven’t tried for super duper accuracy yet and just having fun. As my smoothbores are replicas of military weapons I have been using paper cartridges so far.

Before I even rolled my first cartridge I had presumed the flat of the roundball (sprue cut) should be “down” facing the powder. This made sense to me as the outhouse expert on ballistics. Then read from a current “well known” source that the flat should be centered “up” toward the muzzle and have been loading and shooting that way.
Just read a book from the apparent grandfather of the sport (Sam Fadala) who flips the apparent current thinking and states the flat should be facing the powder.

Do we have any real science or thorough testing on which way the ball flat should be facing? Up or down?

The sprue should be facing down, since most cadt balls have small air voids in the sprue area below the surface. A cut cross section of the ball will show this.
So at least in theory, putting imperfections at the trailing edge will give the ball a “ badminton “ effect and reduce the chances of the slowly spiraling ball destabilizing a little if the ball was cast in a mold that leaves a pronounced protrusion if the sprue plate does not cut close enough th the ball. The Lee molds do not leave this protrusion.
But most of us load with the sprue up because it is simply easier to see where the sprue is. Loading with the sprue down makes it difficult to see where it is.
I believe that it does not matter all that much with a well cast ball whether the sprue is up or down. Only the best shooters using the best barrels with the best loads would be able to notice any difference.
I have gotten in the habit of tumbling my cast ball to remove any traces of the sprue and position them on the patch like I would a swaged ball, and it works for me.
I will concede however, if sprue condition does matter, it would most likely have some effect in smoothbores, with or without a patch, there being no rotational spin to counteract any small imperfections or variables.

 

[FPDoc]

Off thread but related: Lee advertising indicates that their sizing method of pushing a bullet thru the sizing die nose first, force is applied to the base of the bullet, is superior to the Lyman/RCBS method of pushing it into the size die base first, force is applied to the nose.
Reason any deformation of the nose contributes to loss of accuracy. A sprue or mark of a sprue would be a deformity.
Just a bit of trivia.

Technically you can use special dies to bump the bore riding portion of a bullet to better fit your particular barrel bullet combination and increase accuracy (not a criticism just another fun fact comment). Do what works best for you.

"Well, Jane, it just goes to show you, it's always something! If it's not one thing, it's another!"
~Rosanne Roseannadanna (Gilda Radner from when SNL was funny)

 

[J. Paul]

Well it makes sense that a flat spot on a “sphere” would have a effect on flight characteristics. Guess the ultimate question is: Is the effect worth worrying about and, if so, how do you minimize it.

Muzzle Blasts magazine did had a article about this about 15 years ago. The also addressed question of holes or voids in home cast round ball having an effect on accuracy. The author drilled holes of various depths into several ball then loaded and fired at a target then compared results. Their conclusion after several dozen shots was that sprue up down or sideways ultimately made no difference unless patch was damaged. Yhey also loaded the balls with drilled holes, some hole up, some hole down, the rest ball to side at various angles between up and down.
Virtually all hit to same point as aimed at. Their conclusions were that location of hole made no difference. What they found was the ball while spinning in flight found its own balance around its center of mass was self stabilizing in round ball.

 

[ord sgt]

My Lyman mould leave a sprue. When I load the ball, the sprue is on the top. My short starter flattens the sprue when I first start the ball, then the ram rod further flattens the ball when it is seated on the powder charge.

 

[FPDoc]

" ...most cast balls have small air voids in the sprue area below the surface. A cut cross section of the ball will show this".

If you leave an adequate "button" over each cavity when casting it will provide a small amount of molten lead for long enough to prevent or severely reduce the size of the potential shrinkage cavity.