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Ever cast a bad batch of Roundballs?

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It seems to be a consensus at the castboolits forum that variations in bullet weight don't matter much. Especially for pistol bullets.

However if weight doesn't matter, and there are no obvious deformities is it possible to have a bad batch of cast RBs?

I have been have problems with a rather sudden and inexplicable accuracy loss. All the cast roundballs look fine. Later I tried casting new batch. This time I powder coated the new ones so I could tell them from the old ones. Next time out I only had enough time to shoot 4 of the new ones. Much improved accuracy! But that was only 4 shots.

The weight spread on the new RBs is 2.1 grains for a .530 ball (less than 1%).

If th previous batch all had uniform appearance on the outside, and weight variation does matter, what does? How can one batch perform much better than another?
 
Weight variation has to matter. The projectile is round, if there is weight variation it can only mean the diameter is varied or a void internally. Both will impact accuracy. The diameter difference means a difference in pressure within the bore (think patch thickness) which means different impact point. A void means spin will be affected, thus sending a “flyer” outside the group.
Handguns are not shot far, and I don’t think things will be noticeable at 15-20 yards.
Walk
 
It seems to be a consensus at the castboolits forum that variations in bullet weight don't matter much. Especially for pistol bullets.

However if weight doesn't matter, and there are no obvious deformities is it possible to have a bad batch of cast RBs?

I have been have problems with a rather sudden and inexplicable accuracy loss. All the cast roundballs look fine. Later I tried casting new batch. This time I powder coated the new ones so I could tell them from the old ones. Next time out I only had enough time to shoot 4 of the new ones. Much improved accuracy! But that was only 4 shots.

The weight spread on the new RBs is 2.1 grains for a .530 ball (less than 1%).

If th previous batch all had uniform appearance on the outside, and weight variation does matter, what does? How can one batch perform much better than another?
Often debated from both sides. Guess it depends on your definition and expectation of accuracy. Me, I weigh mine, typically keeping the ones within 0.5 grains of the heaviest, more or less depending on diameter. Liken voids or air pockets in the lead ball to the trick baseballs we had as kids with off center weigh that would wildly move around when we threw them. Same principle with a lead round ball? Don’t know, but find the ones I weigh group better.
 
Consistency is going to be the key to accuracy. Chaos can always sneak in and bite you.
Ml are designed to be inconsistent. You can over come that. The more consistent you can be the better, and that includes the same weight of ball, or as close as you can.
That said I have never weighed a ball. If it looks good it flys.
 
I wonder if it matters more for RBs tha bullets. My understanding is that the weight desrepencies can be caused by air voids which usually are directly beneath the sprue. If you load sprue-forward, this puts the void on the axis of rotation and it shouldn't make a difference. However, I have a difficult time centering the sprue perfectly, and commercial balls don't have a sprue (but they have voids).

With cast bullets on the other hand, the void will naturally center on the axis because the projectile's shape dictates how it fits in the bore.

But my question still stands. Has anyone ever cast a bad batch of balls that appeared good, but caused accuracy to suffer?
 
I doubt the sudden loss of accuracy is ball related.
Try replacing the nipple with a new one.
 
I find that when I suddenly have a loss of accuracy, the culprit is more often than not...me! Muzzleloaders offer a myriad of ways to be inconsistent. Admittedly, I've been guilty of most of them.

I can't say that I've cast a bad batch of balls, and I'm with the if it looks good it will shoot group.
 
It seems to be a consensus at the castboolits forum that variations in bullet weight don't matter much. Especially for pistol bullets.

However if weight doesn't matter, and there are no obvious deformities is it possible to have a bad batch of cast RBs?

I have been have problems with a rather sudden and inexplicable accuracy loss. All the cast roundballs look fine. Later I tried casting new batch. This time I powder coated the new ones so I could tell them from the old ones. Next time out I only had enough time to shoot 4 of the new ones. Much improved accuracy! But that was only 4 shots.

The weight spread on the new RBs is 2.1 grains for a .530 ball (less than 1%).

If th previous batch all had uniform appearance on the outside, and weight variation does matter, what does? How can one batch perform much better than another?

Percentage is irrelevant. When casting bullets for match rifle use (BP brass suppository) I keep them withing -1 grain. Otherwise there will be significant internal flaws. I went so far as to glue a selection or weights to a board trued in the mill and machined down through them .010" a pass. I stopped keeping anything more than -1 grain from nominal after that. In this case 1 grain is about 0.25%. But its enough to cause issues. Also note that every lot will have a different nominal weight. So I cast until the pot is very low. Refill, let it heat and normalize then start casting. But these are then a different weight lot and will not "cull" the same as the previous. Or even if you stop casting and come back a hour or days later they have to be considered a different lot. Have you compared accuracy with Speer RBs? Are you sure the patch material is good. Some or maybe all the communist made ticking is weak and can fail to some greater or lessor degree. And it can be random. Finally in a slow twist barrel things are not as critical as in a fast twist. But if you bother to weigh them keep them within a grain. Heavier usually has no voids.
 
I wonder if it matters more for RBs tha bullets. My understanding is that the weight desrepencies can be caused by air voids which usually are directly beneath the sprue. If you load sprue-forward, this puts the void on the axis of rotation and it shouldn't make a difference. However, I have a difficult time centering the sprue perfectly, and commercial balls don't have a sprue (but they have voids).

With cast bullets on the other hand, the void will naturally center on the axis because the projectile's shape dictates how it fits in the bore.

But my question still stands. Has anyone ever cast a bad batch of balls that appeared good, but caused accuracy to suffer?

Cast bullets for cartridge use are generally run through a sizer which may help a lot with forcing some uniformity. We don't do this with round balls, so they are "as cast." I think with conicals that we jam down the muzzle, we are "sizing" them on loading which may also help with forcing some uniformity.
 
In the first place, the question refers to round balls.

From the O.P.

"However if weight doesn't matter, and there are no obvious deformities is it possible to have a bad batch of cast RBs?"

Percentage is irrelevant. When casting bullets for match rifle use (BP brass suppository) I keep them withing -1 grain.

Sorry, have to disagree with that one.
One grain difference in a .350 ball (65gr) is a 1.7% massive defect. It's going to wobble - A LOT.
One grain difference in a .575 ball (231gr)is less than .4 % and in accuracy is undetectable.
One grain difference in a .735 ball (598gr) is less than .2%, one I would consider almost perfect.
Besides that, we don't talk about "unmentionables" here....
 
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Do you keep stirring and skimming the pot as you cast? or is it best to only skim the slag once, then quit casting before the pot gets 3/4 empty?
 
I skim before starting casting and then again if slag floats on top again. I use a dipper to cast so it will agitate the lead as I cast. I’ve cast bad individual balls, but not a batch unless the lead was contaminated with zinc(unmentionables). If you have soft lead that is close to pure you shouldn’t have a “bad” batch.
 
Seems odd that we are only focusing on weight imbalances and not taking into account symmetry of the projectile. To me symmetry would be the bigger factor.
We can measure symmetry, not sure how you would measure a void inside a ball.
 
Do you keep stirring and skimming the pot as you cast? or is it best to only skim the slag once, then quit casting before the pot gets 3/4 empty?
There will be a lot of different opinions on that question ...
The answer may have a lot to do with how you cast. Bottom dump or dipper?
SO... this is what I do and have been doing for a very long time.... with my BOTTOM DUMPER
Load the pot and heat it up to casting temp, flux with beeswax, candle wax or your choice of carbons...
Stir, deep and use the small spoon or ladle to scrap the sides of the pot and loosen up everything you can.
When the smoke clears, skim and discard the crud. I keep a tin can handy to receive the skimmings.
I will then cast for about half the pot, maybe more-maybe less til I need to take a coffee break. I will reload the pot until full and go get a cup.
When back to casting temp, I will reflux and skim, then start casting again.
BTW - I have a hotplate in my lineup to keep molds the right temp. Been at it so long I have the settings near perfect.
If you are dipping, it's probably a good idea to skim a little more frequent unless you have a bottom feeding ladle.
I find that time spent at the casting table is not detracted from your allocated time in this life. It's a blessing.
HAPPY CASTING!
 
Do you keep stirring and skimming the pot as you cast? or is it best to only skim the slag once, then quit casting before the pot gets 3/4 empty?

I skim as need, some lead is "dirtier" than others. I also scrape the sides and bottom of the pot when skimming. I never let my pot (bottom pour) go completely empty unless I thoroughly scrape the inside first, and I don't run the last little bit through the spout. I pour it out.
 
Seems odd that we are only focusing on weight imbalances and not taking into account symmetry of the projectile. To me symmetry would be the bigger factor.
We can measure symmetry, not sure how you would measure a void inside a ball.
I of course, am assuming the ball is actually round and the mold is in tolerance.
Out of the hundred or so molds I have, I have only received one mold that was not, a Lyman .735 RB and it got replaced under warranty.
A void inside the ball is detectable by weighing them. Dutch addresses this in his book (HIGHLY RECOMMENDED). A void inside the ball means it will not spin without wobbling.
Of course, if you are shooting a smoothie, that may not matter???? (No spin)
 

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