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How are homogeneous solids manufactured?
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I'm pretty sure nobody makes money having a CNC machine do it. Are they swaged? Cast? Cut on a machine? What alloys are used? Bronzes run about as hard as steels. How do you not blow up your gun shooting them?

There are lots of little brass and bronze fasteners and other small objects at the hardware store that sell for pennies apiece. Many of them are more complex in shape than a bullet.

I'm mostly interested in knowing so I can start another hobby: thinking about how a hobbyist would tool up to do this.

H. C.
 
Posts: 3691 | Location: West Virginia | Registered: 23 May 2001Reply With Quote
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I have been told that replying to my own posts will make hair grow on the palm of my hand. I'll let you know how that turns out. At certain risk, I just remembered the idea I had a few days ago.

Some metal objects are fabricated using explosions. Fireformed cartridge cases are a mundane example. Would it be at feasible to make a steel die with a cavity much like a bullet mould, with a short gun barrel leading into it, so as to form a bullet?

The idea is to load a brass, bronze, lead, or whatever soft metal rod of maybe slightly undersized round stock into a cartridge case with a to-be-determined powder charge and fire the piece of round stock into the die. There might have to be vents in the system, and the die itself might need to have a vent hole at the nose end. If the powder charge and barrel length are right, maybe the whole thing won't blow up, and you get one nicely formed bullet each shot.

Anyone ever heard of this being done?

H. C.
 
Posts: 3691 | Location: West Virginia | Registered: 23 May 2001Reply With Quote
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Well, there's maybe a little peach fuzz getting started. Or maybe my vision's getting blurry. Hard to say.

The only other method I can think of offhand to fabricate metal objects of a precise shape uses powdered metals. I understand that if you press or whack the particles together hard enough, they weld together into a solid mass. Remington discusses this on their web site.

One of the Corbin brothers told me you can press an armor-piercing tungsten solid starting with the powdered metal containing some small percent microcrystalline wax. Regular bullet swaging equipment will do that job for you.

The last way that occurs to me is that you could put a mixture of powdered metals into an ordinary bullet mould and heat the mould hot enough to melt the lower melting metal. A mixture of copper powder and tin powder would give you bronze. Copper and zinc would give you gilding metal or brass depending on how much zinc. If need be, you could heat an iron bullet casting mould hot enough to melt the copper too. Maybe a suitably dense Babbit metal alloy that is is soft enough to take the rifling could be made in situ using this method. The nice thing about bullet moulds is that you can have crimping cannelures and even multiple grooves (like those fancy GS Custom bullets) to reduce bearing surface and reduce chamber pressure.

H. C.
 
Posts: 3691 | Location: West Virginia | Registered: 23 May 2001Reply With Quote
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I think the homogeneous bullets are made the same way sintered bearings are made- with powdered bronze under high pressure. I don't know if the bullet is made to the final dimensions this way, or is machined and/or sized that way.
 
Posts: 345 | Location: Michigan | Registered: 09 February 2003Reply With Quote
<PaulS>
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HenryC470,
The process is one of pressure. Any kind of pressure will work as long as there is enough of it. You will need a press - one that will produce 25 to 50 tons of pressure per square inch and some heavy dies made from carbide. You will need either sintered metal (not recommended because after forming it still separates at those same boundaries that were there when pressed unless you generate enough heat to liquify the metal) or some very uniform rod stock and a way to cut precise lengths (weights). Take your core, place it in the die, put your die together with the plunger in place and insert it in the press. Start it up and press it to the correct pressure and push it back out of the die. Now you have one bullet.

By the way you can get the equipment and supplies for solids / homogenous and jacketed bullet swaging from Corbin. The dies will cost you more than a reloading setup and the presses are more expensive. The supplies are also available for the different kinds of bullets at an appropriate cost.

PaulS
 
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The powder metal process involves compressing metal powder in a die then sintering it.Remington has long made such parts ,specializing on high density (equivalent to wrought) parts which requires a second pressing and sintering process.Sintering shrinks the part from die dimensions.A newer powder metal system (MIM) mixes the powder with polymer (wax) which is injected molded .The part is then heated, first to drive off the wax then at higher temperature to bond the metal particles.There is considerable shrinkage in this process. Unless special care is taken powder metal parts tend to be a bit brittle. Bullets also could be made by compressing copper or bronze into a die. But it seems to me that it would be far easier to machine them especially when using a design like GS.
 
Posts: 7636 | Registered: 10 October 2002Reply With Quote
<hd352802>
posted
Henry, the solids I have are just turned brass from a lathe,easy and unbelievable simple to do,
if you own a lathe....
Turned bullet prices are way to high for what it is.The ones I have can be made at a rate of about
100 an hour,without anybody interfering.
If you own just a small lathe, many people do,you can make several bulets an hour, depending how handy one is with it.

Hugh.
 
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