Bronze Casting

Hello Friends!

A few questions I wanted to raise as YouTube has been very uninformative so has Google. I am not a chemist by no means but do have a few questions that hopefully someone would be willing to answer. Currently working with ATF on getting my type 07 & 10 FFL (currently 01) as well as my FEL. However, a few questions like I said. lol

1. The use of bronze for boolit casting. What are your thoughts? What are the pros and cons for having pure bronze cast boolits? How does bronze impact the rifling in a barrel? I know its softer than steel, but don't really know its impact. So this would apply to both pistol and rifles. Hence why you see a type 10 FFL up above lol. ATF defines bronze as an "armor-piercing" alloy. In anyone's personal experience, would pure bronze actually penetrate armor?

2. Molds (moulds) to cast bronze with. I see most molds are made of aluminum, brass, and steel. I know certain metals cannot be combined with other due to them being ferrous and non-ferrous and one binding with the other. However, not a chemist so I honestly dont know if molten bronze could be cast in one of those types of molds or if this is a situation where a carbon mold would be needed. Thoughts?

P.S. I havent really found anything in regards to bronze casting of boolits. This could very well be because either A. they are not suited for flight or B. the cost of bronze is just too expensive and people do not wish to try. or C. they are defined as AP. However, that doesnt negate my questions.

This might also be one of those cases where you would turn out better with a lead boolit with a bronze penetrator. However, not sure if bronze would even penetrate.

Bronze bullets are not normally cast, they are turned on screw machines. You can buy leaded bronze rod to run in your machine. Also be aware there are about 1000 different bronze alloys and only a handful are suitable for making bullets. The extreme long range guys love them, since the shape can be varied easily by changing the program and the noses can be made razor sharp. They are also used quite a bit in African loads for deep penetration on buffalo and other heavy game. An example is here:
https://cuttingedgebullets.com/shop/...ets?caliber=55

These are mostly copper or brass but the idea is the same. And there is no reason you couldn't make pointy tips to insert into cast hollow point bullets either, Remington used to make bronze tip ammo like that. It tends to open up really fast and come apart rather than penetrate deeply.

Good info here! Given the fact they are not normally cast would lead me to assume that is why there is so little info online regarding it. Given that a screw machine is involved lol. That sounds like several racks right there given the word "machine". Could also explain why one thread i saw mentioned they would have to be cast in carbon if they were cast.... I guess due to its melting point? or the fact it binds easily with other metals?

I guess this is one of those where I gotta do some serious R&D and find what works. Yes, I am a long range kinda guy. I swear I wouldn't give up my .338 Lapua for anything.

But the question remains. Is bronze really an armor piercing alloy (or could be an armor piercing alloy, depending on its composition)?

Also, thank you for that website as well.

Bronze melts around 1700 degrees F. I have done foundry work casting bronze hardware - it’s not for the faint hearted. I can’t imagine producing bullets without a die casting machine and tooling - or a big hydraulic setup and cold forming.

That being said, Nobade described the easiest way to make bronze projectiles with the least investment. You could probably pick up a small cam-Swiss lathe (Tornos is one make) and a single bar feeder. However, you will have to grind your own cams or have someone make them.

I don't know about bronze specifically, but metals normally can't be cast like lead bullets. Lead is one of the rare metals with a low melting point, and the right properties to fill out a mold with no further help. Zinc can apparently work ok with a few tricks. By the time you get to aluminum and magnesium you will need pressure injection in the form of die casting to get any kind of reasonably consistent part. I have heard of some copper die casting. I don't believe any bronze alloy can be die cast. Those will have to be something like a sand mold, and you can't get super consistent parts that way, not to the level needed for bullets. Instead when you are talking about bronze and smaller parts like that, it is either A. machined, or B. sintered. You won't be able to afford the machinery needed to create sintered bullets.

In years past, one company produced some bronze bullets.
With a bit of a point, they pierced the levels of armor plate used in armored limos. and body armor.
They trashed a barrel pretty fast too.

The ATF more or less told him that if he went into production with them,
they'd come after him in a black helicopter.

So I started looking into the machinery needed to machine them and its not bad in price it was like $8,000. That's affordable. However, I thought bronze was softer than steel? I guess with repeated use fired from a barrel it could give some wear and tear. I guess this is where the lack of chemistry comes into play. Yea, I know ATF would be looking at me with a mag. glass and I am fine with that. The machine makes it look so easy, but I have no idea who or where to turn to get the CAM designed from. (The instructions on telling the machine how to draw it). Its also not just bronze its really any alloy that is softer than steel. Unless im going for a barrel made of Tungsten carbide lol... Then i guess really anything could be manufactured and shot from that. I still think about ATF showing up in a black helicopter LOL. I honestly am not worried. AP rounds could prove useful for our men in blue, especially given criminals these days are walking around in body armor likes its nothing. But really this was about the alloy itself.

Its all really about R&D and finding something that gives the good guys the advantage.

https://apsx.com/apsx-nano-cnc-swiss-lathe

That is what I was looking at.

The CAM? Do you mean a CAD, like in Solidworks?

No I don't think bronze is a good choice for an armor penetrator, not significantly better than a FMJ anyway. Steel core has been around for a long time for that purpose.

No it isn't that easy to make solid hard bullets. It took a long time for Barnes to get it right. You are talking like you want to make a bronze core bullet, which just seems like a strange idea. You should just make the entire bullet of copper at that point. I say copper because I've never heard of a bronze alloy bullet.

No I don't think this is a good venture for you. This isn't an insult, but you don't seem to have any kind of grasp on engineering or CNC machining. I'm really confused why you would be willing to drop $8000 on a machine you don't know how to use, to make a product you don't know how to make.

Quote:

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Originally Posted by megasupermagnum

The CAM? Do you mean a CAD, like in Solidworks?

.

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Old style cam actuated machines are still very efficient and way too economical to die out anytime soon. Yes they are being replaced by CNC but they are still widely used.

https://www.thomasnet.com/insights/t...ng%20workpiece.

Cam-Operated Screw Machines/Lathes

Cam-operated screw machines are mechanically automated by a series of disc cams. Becoming popular in the late 1860s, rotating cams transform rotary movement into linear movement. As the cam rotates, linear motion is used to advance the cutting tools to the rotating workpiece. This type of equipment was the first type of automated screw machine. Although now largely replaced by CNC-operated machines, cam-operated screw machines continue to be widely used in many fabrication workshops.

Screw Machines Through the Ages

Since they were introduced more than 150 years ago, screw machines have seen several changes and advancements. Manual methods have become obsolete, replaced with cam and CNC automation. Although CNC machines are more commonly used and offer several advantages over mechanical cam automation, cam-operated machines are still employed in many types of machining applications.

The best option for your machining job will depend on the specifics of the application at hand.


https://www.youtube.com/watch?v=ga9T70S1XTg

Thanks M-Tecs, I leaned something, however I do not believe that linked lathe operates like that. It definitely says CNC lathe, which would require a CAD program.

Quote:

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Originally Posted by megasupermagnum

Thanks M-Tecs, I leaned something, however I do not believe that linked lathe operates like that. It definitely says CNC lathe, which would require a CAD program.

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It uses its own software and G&M-code and MDI commands are always an option.

https://apsx.com/apsx-nano-cnc-swiss-lathe

APSX-NANO uses the APSX CNC lathe software. You can find a sample g-code file below for download.

Work offsets and manual controls
Cycle controls such as RUN, ABORT and feed rate (override) limit
g-code and MDI control commands
DRO panel and file management

The real issue is will it hold the tolerance required and if it does for how long? Quarter million dollars is normally a starting point for entry level CNC machines that will hold the tolerance the custom bullet makers run.

Some good info here https://castboolits.gunloads.com/sho...ets-on-a-lathe

This is how some of the custom makers do it. https://cuttingedgebullets.com/manufacturing-process

https://www.youtube.com/watch?v=-IC6gYPlWUg

The CNC screw machine is just the start of the costs. Higher tolerance inspection equipment gets expensive fast. A single Mitutoyo Indicating Micrometer,0-1 is around $900.00

Check federal law. I believe that bronze is a no no for pistol ammo, but IIRC is used for some civilian loaded 50 bmg rounds.

I have not see any tests for bronze on steel. If pointed it might better penetrate Kevlar than jacketed bullets. The only maybe bronze ap rounds that I ever save were old .357 magnum solids that I think were something similar to bronze.

Smaller scale and second op needed for the base. Tough to hold tolerances require for the long-range match bullets on this type of set-up.

https://www.youtube.com/watch?v=-s61tXCVr6Q

https://www.youtube.com/watch?v=zfDObdkxFOA

From the sounds cutting brass rigidity with be an issue. This machine is a toy.

https://www.youtube.com/watch?v=LxB4pNiAVVs

catch being bronze rod of any formulation is ultra expensive .....and turning a fair fraction of it into chips which wont fetch $2 a lb as scrap...........any mass production of bronze bullets would be by swaging,ie pressure forming.........in any case bronze bullets are so WW1 (balle D) production has moved on to sintered iron cores and steel jackets ,possibly copper washed for appearance ,or just phosphated to hold a bit of hard lube.

In 1898 the French government replaced the original balle M bullet on the 8x50mm cartridge (worlds first smokeless powder cartridge) with the 198 grain solid bronze spitzer boat tailed "balle D" bullet. This was for use in the model 1886 Lebel rifle. All the design work for the industrial manufacture of a modern style solid bronze bullet, and its effects on barrel wear, as well as suitability for use under adverse conditions, was done over 120 years ago. You don't have to chisel a wheel out of stone if you can just buy one off the shelf. Whip out the Google-fu and research the balle D to see what alloy composition, ballistics and manufacturing information is already available. Yes, modern CNC technology is available today to simplify manufacture, but a lot of the technological heavy lifting has already been done for you.