zinc bullets

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  • Last Post 08 December 2011
CB posted this 12 April 2011

Has any one ever cast zinc or babbit? Was wondering about it as bullets to use for paper patching. If you paper patched it , it would not touch the barrel so there would be no significent contamination or would there be. What would the bullet weight be in comparison with W/W or 50/50.

beekeeper

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LWesthoff posted this 12 April 2011

The NRA Cast Bullet handbook (copyright 1979; last printing I know of 1982) has a couple of articles about zinc bullets. One of them, which firsrt appeared in the Mar. '58 Rifleman, talks about using Zamak, a zinc die-casting alloy, in rifle bullets for the 30-06. The other one, which first appeared in the Oct.'77 Rifleman, talks about zinc die-casting alloy for pistol bullets. The author says they need no lube or gas checks, are very hard, weigh about 60% as much as the same bullet cast of “lead alloy", and both the writers (these both appeared as letters to the editor) say they experienced no fouling even with unlubed bullets at jacketed bullet velocities. Being so light, their BC would be pretty low, and they'd lose velocity pretty fast, I think.

I was never trempted to try casting/shooting one.

Wes

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melchior posted this 28 November 2011

Over the years I recall seeing a couple of articles in The Fouling Shot from a member in Australia who has been casting in zinc.  The most recent is in #214.

Personally, I'm quite interested in this topic and would like to know a lot more about it.  If there are enough others out there maybe we could turn this thread into it's own forum topic.

It appears that there are going to be more and more political difficulties with lead alloys and I think that even with the poorer BCs zinc is cheap enough to provide lots of good fun for shooters.

So let's hear from anyone else who has information or opinions on casting zinc bullets.

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72coupe posted this 28 November 2011

Question? Wouldn't the shape of the bullet not the weight determine the BC?

It would determine the sectional density.

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melchior posted this 28 November 2011

Isn't sectional density a component of BC?    :thinking:

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72coupe posted this 28 November 2011

I was asking. I don't know.

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melchior posted this 28 November 2011

"In http://en.wikipedia.org/wiki/Ballistics>ballistics, the ballistic coefficient (BC) of a body is a measure of its ability to overcome air resistance in flight. It is http://en.wikipedia.org/wiki/Inversely_proportional>inversely proportional to the http://en.wikipedia.org/w/index.php?title=Negative_acceleration&action=edit&redlink=1>negative acceleration”€a high number indicates a low negative acceleration. BC is a function of mass, diameter, and http://en.wikipedia.org/wiki/Drag_coefficient>drag coefficient. It is given by the http://en.wikipedia.org/wiki/Mass>mass of the object divided by the http://en.wikipedia.org/wiki/Diameter>diameter squared that it presents to the airflow divided by a dimensionless constant i  that relates to the aerodynamics of its shape. Ballistic coefficient has units of lb/in² or kg/m². BCs for http://en.wikipedia.org/wiki/Bullet>bullets are normally stated in lb/in² by their manufacturers without referring to this unit."

http://en.wikipedia.org/wiki/Ballisticcoefficient

I could always be wrong, but I think the mass/diameter part of the above definition is what I meant by the sectional density being part of BC.

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CB posted this 29 November 2011

72 Coupe

To answer your question in plain language the BC depends on BOTH the shape and the density (Mass per unit volume) of the bullet. Lead has a higher density than Zink which has a higher density than styrofoam, etc.

BC is directly dependent on the density. For two bullets of the same shape and size of two different materials where one material had twice the density of the other, the one of the higher density material would have sectional density twice as high. And since the two bullets have the same shape they would have the same drag coefficient. Thus the bullet of the high density material would also have a BC twice as high.

Shooting wooden, styrofoam, and lead bullets of the same shape would illustrated the virtue of a dense bullet. That's why some anti tank bullets are of the very dense depleted uranium.

I hope this helps.

John

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codarnall posted this 30 November 2011

I have cast it, shot it and hate it. Commonly known as Kirksite. The USA used in in 45-70 training rounds. In lead the same form factor as a 400 gr these were 200gr. In a 311466 instead of 150g the slugs were about 60 gr. The stuff melts at about 900-1000F. Do keep it away from any of your lead stock. Some slugs traveled through 6” of pine w/o a scratch on the bullet. Advertised as low melting point casting metal of Zn and Al you may like it if you know what it is to start with. I didn't and I am still pissed.

Charlie

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melchior posted this 30 November 2011

I fully understand about the light weights, but it seems that for short range use, especially target, it should work well.  No??

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codarnall posted this 30 November 2011

I believe the USA used them strictly for short range. The USMC having less of a budget used the 1000 inch range with the butts man marking a pin prick when the flag was indicated sight and tgt alignment. Not as nearly dangerous either. Bullets were massless and traveled at C.

Charlie

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daboone posted this 08 December 2011

codarnall wrote:Bullets were massless and traveled at C.Charlie

:thumbsup::D

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