Magnetic brass!


#1

I started a new thread following this one as the side effect I do object on is so unusual I thought it deseved an own topic:
iaaforum.org/forum3/viewtopic.php?f=8&t=14841

I convinced the owner of that Hungarian headstamped 7.62x51 to pull the projectile so we can examine it closer.
It turned out that the projectile used is an Impala hunting projectile:
impalabullets.at/index_intro_en.html

The odd thing now is that the projectile is made of solid brass (a friend confirmed that from the factory). Nevertheless the projectile IS magnetic!
Not as magnetic as solid steel (actually only iron, cobalt and nickel are magnetic) but still magnetic enough to be attracted by a strong magnet.
The question is now if the brass alloy used is containing nickel as I think the two other materials can be ruled out.
Any thoughts on that or did somebody observe this before?

Here an image (no photoshop or cheat!):


#2

In one of our sales, some years ago, we had a tinned brass Parker shot gun shell (can’t remember if fired or new primed empty but not a loaded shell) which was mildly magnetic. It did not have a steel or Iron anvil if it was a Berdan shell.
No idea why, 99.99999 of them are just brass or plated brass and are not magnetic. So total mystery then & now.
As you most likely know a lot of shot gun shells do have an inner steel reinforcing at the head but those are paper bodied, not all-brass.


#3

The terms “brass” and “bronze” are sometimes confused, and I wonder if the bullet is anything like “Aluminum bronze” which is attracted to a very strong magnet. I had been wondering this about a Libra Snail keychain bullet which had these properties in this thread: http://iaaforum.org/forum3/viewtopic.php?f=8&t=11319 .

Is the magnet in the photo attracting your rifle bullet of average strength or is it extremely strong? If it is only a weak to average strength magnet and it is picking up the bullet, then that is very strange.

Aluminum bronze: http://en.wikipedia.org/wiki/Aluminium_bronze


#4

The magnet appears to be a rare earth magnet they are extremely strong.
Neodymium.


#5

[quote=“DKConfiguration”]The terms “brass” and “bronze” are sometimes confused, and I wonder if the bullet is anything like “Aluminum bronze” which is attracted to a very strong magnet. I had been wondering this about a Libra Snail keychain bullet which had these properties in this thread: http://iaaforum.org/forum3/viewtopic.php?f=8&t=11319 .

Is the magnet in the photo attracting your rifle bullet of average strength or is it extremely strong? If it is only a weak to average strength magnet and it is picking up the bullet, then that is very strange.

Aluminum bronze: http://en.wikipedia.org/wiki/Aluminium_bronze[/quote]

Matt, the projectile is solid and has no traces of having something inserted or being of a composite construction. Also the manufacturer stated to use brass only. I also got the comparison from what I think must be different lots where a friend said his Impala projectiles are definately not magnetic.

Bronze would be more reddish on color to what I have seen in the past. Also bronze should not be magnetic then unless tha alloy would contain one of the three magnetic metals.

Do brass alloys with cobalt or nickel exist?

As we see in the image the projectile is barely held by the magnet, means the magnet can not hold the projectile to lift it completely despite tha magnet is quite strong for it’s size.

@Sportclay
I am not much into magnets as such. Would the type of magnet influence the magnetic properties of normally non magnetic materials? I tried with otter brass items (cases etc.) and nothing happened.


#6

The U.S. system of naming alloys is somewhat confusing. While a zinc alloy with 95 percent copper is called gilding, one with 90 percent copper is called commercial bronze (alloys 210 and 220 according to MIL-C-21768).

If something is attracted by a magnet (neodyme or not) it must contain some material with magnetic properties and cannot be a pure brass alloy. I am really surprised that the Impala bullet is attracted by a magnet, to put it mildly. But this can only mean that something else than copper and zinc must be present.


#7

I am not a metalurgist. However, my father is and according to him the alloy would have to contain Fe, Ni, or Co in some quantity. There are companies that make brass and aluminum and other metal alloys that are magnetic to some degree for use with sensors and combined with the need for a specific application of a softer or more maleable material. Why a bullet would be constructed of a slightly magnetic brass alloy would be conjecture on my part. The degree of magnetism in some of these alloys can be greaty affected by temperature and exposure to certain radiation.
Interesting use of this alloy. Perhaps it was surplus and affordable from a metals/material supplier???

thomasnet.com/products/magne … 608-1.html
this is a link to suppliers of specialty alloy manufacturers.


#8

My thought exactly. The brass supplied was either an over-run, rejected or contaminated (knowingly or unknowingly) and the end user got it for a good price…

AKMS