Lead Balls?

[Brian Rice]

What is the differnce in Swagged and cast balls except for the swagged not having a sprue? Is one or the other more accurate or consistant in weight and diameter?

 

G'day Brian,

Swaging is, without excess detail, the pressing of a known weight of metal into a die under very high pressure.

Cast bullets are made by melting an alloy or pure lead and letting it flow into a mould. When it is hardened the sprue cutter is used to cut off the metal left outside the mould as a result of the casting process.

The biggest problem with casting is small air holes or impurity. The air trapped in the finished ball will reduce the weight of the ball and may also make it dynamically unstable. You might say the round ball will tumble. (Yes I know what some of you will say. :what Impurities and air bubbles could be critical in a hollow base projectile used in a breach loader as it may separate. If another projectile is put up the barrel with the skirt of the previous still in place it is likely the barrel will bulge or be ringed. In the front stuffer the skirt would be pushed down onto the powder charge and will come out with the new shot. There would be a small possiblity, in this example, for the barrel to be ringed again if there is an air space between the powder and the projectile.

Bottom line. Swaging is more uniform and more expensive usually. Casting is more likely for the blokes like me and for me it does everything I want except I will not cast hollow base projectiles for any breach loader. If you want more on swaging look up Corbin as he makes most of the big swaging tools.

Cheers from down under
Aussie Bob

 

[flaming canvas]

Swaging is probably not practical as a method of home production of round ball. It would take a lot of pressure to form the ball and possibly more than one step.

Looking at some Speer and Hornady ball, I can see a lot of small facets, whereas the ball I cast are much smoother and more uniform. I would bet on cast ball being more accurate if good casting practices are followed. :m2c:

 

[Stumpkiller]

I agree with what's been said. I weigh every cast ball and reject 0.2 gr +/-. It means I must recast 25% some runs, but it produces very consistant cast ball accuracy. It's amazing that some cast balls can look perfect, but be 5 gr off nominal.

 

[pepperbelly]

flaming canvas I noticed the small facets on my Hornady balls also. I thought they were from being packed in the box and stacked, handled, etc.
Do they affect accuracy, since the ball isn't prefectly round? I know none are perfect, but these are easily visible.
Jim

 

[rayb]

Let's think about a golf ball and the dimpled surface it has. the dimples cause the boundary where laminar flow around the ball changes to turbulent flow in the fluid (air) to move back toward the rear of the ball. This reduces the size of the turbulent wake behind the ball and lets it have less drag and therefore travel further.

SO: some dimpling on the ball surface should be a good thing, provided the balls are of the same weight and are free of voids that could cause instability.

Fluid mechanics books often have pictures of bowling balls and golf balls to illustrate this effect, if you wanted to pursue it.

It might be an interestin experiment to check velocity with smooth vs dimpled lead balls to see if the effect is measurable with the sizes of balls we shoot.

rayb

 

[RussB]

I agree with what's been said. I weigh every cast ball and reject 0.2 gr +/-. It means I must recast 25% some runs, but it produces very consistant cast ball accuracy. It's amazing that some cast balls can look perfect, but be 5 gr off nominal.

Stumpy...You shouldn't tell people you're that picky! I would never get a shot off if I was that picky....Perhaps I need to show you how to "speed cast"...... 0 to 60 in 10 minutes flat!
Put a bunch of 'em back, and start again.....0 to 60, put another bunch back.
After about two hours, we end up with about dozen that weight in at 0.2 or less...These we will throw away! If they were all cast "perfect" we would not have all the good excuses that we now use....trust me, speed casting is the way to go :crackup: :crackup: :relax:

Russ

 

[flaming canvas]

Let's think about a golf ball and the dimpled surface it has. the dimples cause the boundary where laminar flow around the ball changes to turbulent flow in the fluid (air) to move back toward the rear of the ball. This reduces the size of the turbulent wake behind the ball and lets it have less drag and therefore travel further.



It might be an interestin experiment to check velocity with smooth vs dimpled lead balls to see if the effect is measurable with the sizes of balls we shoot.

rayb

Must be a physics teacher or an aeronautical engineer to use all those big words. ::

The dimples in golf balls are of uniform size and in a precise pattern. A swaged lead ball that has been banging around in a box has a more random surface so it might not have as predictable of an effect.

As I think I understand the process, swaged ball start as wire that is cut to length and forced into the cavity. I don't imagine the shaping can be done in one step since the difference in shape would not lend itself to a simple process. Since the volume is fixed by the mold, having too large a piece to start with would cause complications when the mold sections come together. Getting the exact amount necessary is not feasible for mass production, so I would expect the initial slug to be slightly underweight; not by much, maybe .1% so that there would be a guarantee of no excess trying to flow out through the cracks.

Now that we have this going, I'm going to have to sit down with a box of factory ball and my micrometer and see what I can see.

 

[rayb]

[quote}

Must be a physics teacher or an aeronautical engineer to use all those big words. ::

[/quote]

Actually a retired combat engineer... ::

One example i looked at showed a piece of sandpaper glued to a bowling ball and dropped into water...the movement of the boundary location was very apparant in the one with a patch of rough surface. So i think that any roughness would cause the same effect and maybe increase velocity. What it would do to acuracy is another matter.

When i get rich i'm going to buy a chronograph and maybe try an experiment with this.

rayb

 

[Rat]

Some kind of device that would dimple a round ball like a golf ball would be pretty "trick" for a BP shooter. Might be of more value for a smooth bore, I'm not sure if you'd see a difference with a ball out of a rifle. But again I've wondered if that would improve accuracy in a smoothie.

I believe that when balls or bullets are swaged/swedged that there is a provision for the excess lead to "squirt" out of an opening. I've never seen any evidence of this on a swedged ball or bullet, but that might happen in the initial step of a multi-step process.

Rat

 

[flaming canvas]

Actually a retired combat engineer... ::

And the anti gunners always think that we are a bunchof knuckle dragging morons.

Actually, I feel complimented when they call me a Neanderthal. The froo froo's wouldn't last 3 days in the environment that the Neanderthals lived in for 200,000 years.

 

[RussB]

Some kind of device that would dimple a round ball like a golf ball would be pretty "trick" for a BP shooter. Might be of more value for a smooth bore, I'm not sure if you'd see a difference with a ball out of a rifle. But again I've wondered if that would improve accuracy in a smoothie.

I believe that when balls or bullets are swaged/swedged that there is a provision for the excess lead to "squirt" out of an opening. I've never seen any evidence of this on a swedged ball or bullet, but that might happen in the initial step of a multi-step process.
Rat

A sphere, or round ball has no excess, only the lack of being completlety filled, the same as a cast bullet.
It may look perfect, but if they don't weight the same there is a "void" in that sphere somewhere.

That "void" will unbalance the ball causing it to drift toward that void no matter where the "void' is located. The axis of the ball is distrubed on center, and the faster the ball is pushed, the worse the effect.

Of course, you can't see a void, and therin lies the problem, whether it is factory or home cast round ball. In swaging, a "solid" core is brought into roundness by pressure and eliminates 99.9% of voids present....now, to add insult to injury, all we have to do is weight a batch of each...one type will be "off weight" just about as much as the other so weighing, and sorting, is the only sure fire way to get a constant weight in roundball.

It is thought by a few that the "dimple effect" would be negated by using a patch. This is a very old theory and has been attempted by some shooters a few years back, in England, if I remember correctly.

The most exciting thing that has happened to roundball, and continues to show a lot of promise, is the addition a monofilament string to the round ball, to work in the same effect as the tail on a kite.


Russ