Aluminum jacketed bullets

[Jeff213]

I was thinking about bullet jacket materials earlier. Why aren't there any aluminum jacketed bullets?

I use aluminum gas checks on cast bullets and push them well over 2000 FPS and they work just as well as copper gas checks, for half the cost.

Aluminum is easier to swage than copper.

Aluminum is cheaper than copper.

Aluminum wears the barrel less than copper.

I did a quick google search about aluminum jacketed bullets and nothing came up, why is this?

Aluminum would be better for cheap (wolf steel / tula type) ammo, as it is not ferrous and would not spark, therefore would not start fires / be banned at some ranges.

Any thoughts on the subject matter?

[MarkInFolsom]

For starters, the aluminum oxide that would form on the jacket almost as soon as the jacket is swaged would wear out barrels pretty fast when fired. aluminum oxide is used as an abrasive in many applications. It is much harder than steel.

[BeFrank]

Aluminum oxide

For starters, the aluminum oxide that would form on the jacket almost as soon as the jacket is swaged would wear out barrels pretty fast when fired. aluminum oxide is used as an abrasive in many applications. It is much harder than steel.

That could be an issue but since the aluminum case corrosion is controllable the jacketing corrosion should be controllable as well. Is excessive barrel wear an issue with 5.7 aluminum bullets?

[Galt]

That could be an issue but since the aluminum case corrosion is controllable the jacketing corrosion should be controllable as well. Is excessive barrel wear an issue with 5.7 aluminum bullets?

What exactly is done to aluminum cases to control oxidation?

[hermosabeach]

The sparking / ban on some rounds is the Bimetal part.... not just the jacket...
my concern is that steel and AL react and eat each other....

I would be concerned that the copper equilibrium would become an AL plated barrel.... And the two metals have an electrical reaction forming corrosion....

https://en.wikipedia.org/wiki/Galvanic_corrosion

[mjmagee67]

Aluminum Oxide also known as Al2O3. You know what else is Al2O3? Rubies, Garnets, and Sapphires all very very hard gem stones. Don't want those flying down my barrel.

[BeFrank]

Not sure if it's the aluminum alloy or a coating but they seem to be good for a few years without deterioration. Maybe its just because most people store ammo in a cool dry place?

[pacrat]

Pure aliminum itself is VERY corrosion resistant. But when alloyed to increase strenght, it changes its structure to a more openly porous crystalin structure and it become much more susceptable to corrosion.

Aircraft Skins are "AlClad" which means the alloy skins have a coating of pure aluminum several thousandths of an inch thick to protect them.

Not a metallurgist. And never played one on a TV soap opera. But that is how it was explained to me long ago when I worked in the Aircraft industry. And why we had to be very, very carefull of the alclad skins. One little scratch in the alclad, and they were rejected.

Aluminum is cheaper than copper. But it is not cheaper to work with when [forming and drawing]. It work hardens with every operation and cracks easily if not handled properly.

By properly handled, I mean reannealing process after every forming operation. Then quickly storing at below ZERO temp to stabilize until the next operation. Much too labor and production process time intensive for making bullets.

JM2c

[Jeff213]

Ok, I have just not had a problem with aluminum gas checks wearing out my barrels yet after several thousand rounds, but I guess this is different than aluminum jackets.


I was just tossing out an idea, thanks for the interest.

[74c5]

No work hardening to control lead expansion.

[ThatFishGuy]

like others, I am no metallurgist. Buy it seems that copper and gilding metal are more malleable (sp?) which makes them more suitable for jacket material. I know brass is also viable as a jacket.

[LynnJr]

A Google search gave me this.

Traditional bullet jackets are made of copper or gilding metal, an alloy of copper and zinc. There are many other materials that are used in bullets today, including aluminum, bismuth, bronze, copper, plastics, rubber, steel, tin, and tungsten.

[bruce381]

""I did a quick google search about aluminum jacketed bullets and nothing came up, why is this?""

Google winchester silvertip, they were aluminium i think collectable maybe now.

[LynnJr]

The original poster is talking about jackets.
Type in bullet jacket material and it is post #4 how bullets are made.

[JagerDog]

I'd guess the same reason Aluminum makes a poor bearing metal vs. copper/copper alloys. I'd be concerned about mucho metal transfer/galling. And yeah..the aluminum oxide prospects. Maybe with lubed pistol bullets, it's not an issue.