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Great to see the fantastic work of hoganscastings!

What I would LOVE to see is a mould for dimpled lead balls, much like a golf ball.

I think the ideal size would be 15 mm lead, and the dimples should be smaller than those on golf balls. Such bullets should - in theory - fly a lot more far than plain ones.

Plus, the grip in the pouch would be better.

Jörg
 

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woow that was a lot of physic, but I to would like to se golfballstyle ammo, if the grip improves then that would enough. But I am shure that there must be a better airodynamic shape then round. Anny ideas?
 

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I have seen a test on TV (in the US) that proved that the dimples in fact also help without a backspin.

Even the website Melchior has posted explains the reason: The air resistance is lower.

Of course there is no "uplift" effect when there is no backspin. However, the lower air restistance will let the ball fly faster.

Jörg

This quote clarifies my point:

"Golf ball dimples are used on all golf balls because a dimpled golf ball has less air resistance than a smooth ball of the same size and weight. This means less drag force and the ball going farther. "

http://www.brighthub.com/engineering/civil/articles/58569.aspx
 

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in the 80th they used dimpels on helmets with success. maybe leadballs are to heavy for this effect, but someone has to try!!!
 

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Yes, they also reduce the drag of a non-rotating object. However, the main contribution in a golf ball is the lift created by Dimples. Even more in lead bullets. A lead projectile retains the largest share of its energy on a typical slingshot distance - the limits of the slingshot are a trajectory bow, wind and magnus effect that take their toll on accuracy and make aiming more difficult.

Here is a calculator that proved to be quite valuable for my research. Enter a typical lead ball caliber and weight, and a typical slingshot velocity. A .45 lead ball with 200 fps starts with 12.8fpe and still has 10fpe on 25 yards.
http://www.ctmuzzleloaders.com/ctml_experiments/rbballistics/rbballistics.html
 

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I think Dankung sells steelballs with dimpels.

For those of us who don't care about rays are welcome to test them out. haha just joking
 

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Slingshot is such a magic thing that in most case only the 'experiment , test ,trial and practice' work well rather than the 'physical theory' .

I dont mean the physical theory is wrong, I mean someone must test and try to see whether he or she applies the theory correctly on slingshot.

So I back up Joerg's ideas very much . It's a great ideas worthing many tries and tests.

I would have improved english more. but I hope my points is clear.
 

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Tex-shooter
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OK, here is my 2 cents worth. I don't think that dimples will make much difference with lead balls because of the density of lead. Now a golf ball is much less dense so the air resistance would have much more effect on it. I have gotten a lead shot so far up a very smooth lake with a slingshot that you could only see the ripple of it hitting with binoculars. Now I don't have a long enough straight water to even take that shot any more. They built a bridge about 100 meters away and I will not shoot over it. -- Tex
 

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Hi Everone
My very first post on the forum said we are makeing a aluminium mould for self casting of lead ammo?
Jusy so happens it is in the style of golf ball .The mould will have two sizes 15mm OD 10 mm OD
we still have to deside on weather to make it a 5 impression of each size or 10 imp.
got to keep the weight of the mould down or the cost for post will be to much all the best .
PS we are keen to improve on the moulds that are out there at the moment so are looking in to a locking device so your hangs are free when casting???
 

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Discussion Starter · #13 ·

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Hi joergS
having been in the foundry game all my working life seen to many people get blarzay about molten metal
it as a nastiy habit of biteing you back when you least expect it. would no like the resposability for some one getting bernt if the clamp is there use it ??? or lose it.
 

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I use molds made of brass and molds made of aluminum. None have locking devices, though the aluminum Lee bullet mold and the reproduction 19th century brass mold both have sprue cutters. My Do It aluminum fishing sinker mold has no cutter. I understand that steel or iron molds require preheating to work well, but my brass and aluminum molds usually cast perfectly from the beginning. My suggestion to Hogancastings is to make your molds of aluminum and include a sprue cutter. And don't forget the wooden handles!

oops, almost forgot. Mythbusters recently did a test of a dimpled car. They took a Ford Taurus, drove it around a circuit and measured the gas consumption. Then they added a layer of modeling clay and created dimples in scale to those found on golf balls. The got a 17% increase in gas mileage, so dimples definitely decrease air resistance.
 

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Tex-shooter
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Has anybody addressed the difference in accuracy caused at the time of release in a smooth projectile and one not so smooth? -- Tex
 
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