@freemo @drewfer Careful you don't end up like this guy:

https://news.yahoo.com/lawyer-dies-hidden-gun-goes-182941782.html

(And is it weird that they used the word "tummy" in describing a fatal injury?)

@peterdrake @drewfer

lol

@peterdrake @freemo @drewfer the article has UK spelling (licence) and tummy is perhaps more commonly used as a synonym for stomach in the UK.

@freemo

>"Thankfully copper and lead is not magnetic... If i am using iron bullets I deserve to get shot int he face :)"

If a bullet is made of a conductive metal and the barrel is magnetic, the bullet will become an electromagnet as it moves down the barrel. The conductive bullet moving through the magnetic field of the barrel will induce currents in the bullet that in turn will create a magnetic field which will attract (or repel) the bullet to the barrel.

But it won't cause the bullet to turn around and come back though, obviously. If fact, lead is a diamagnetic material so when it is near a magnetic field, the induced magnetic field in the lead is reversed so it would repel from the barrel. (I think)

Also, after a few rounds, once the barrel heats up it should wipe out the magnetization in the barrel. However, the bullets could maintain some permanent magnetization after firing because they would be in a magnetic field while they were hot and quickly cooled. (Not sure about that, though.)

@peterwhisker @peterdrake @drewfer

@Pat @peterwhisker @peterdrake @drewfer

> If a bullet is made of a conductive metal and the barrel is magnetic, the bullet will become an electromagnet as it moves down the barrel.

No, but your hinting at a truth...

When non-ferromagnetic material that is conductive moves through a field it is true eddy currents for and opposing magnetic fields form... However these fields would never cause the bullet to change its course, it would only cause the bullet to slow down. So it will not behave as you'd exect a magnetic material to behave.

In fact you can slow something down to such an exctent it will levitate freely above the magnet (if the magnet is the thing moving, such as a spinning magnet). Which further demonstrates it is not attracted tot he magnetic field but rather opposes it (in this case pushing away from the field.).

In other words the attractions and repulsion will only be enough to counter another force, and not enough to "move" the metal on its own in a direction contrary to its trajectory.

So yea, while seems you get the basic idea already its important to note the only real effect would be to slow down the bullet a bit and hit it up.

And yea the heating of the barrel would demagnatize it but I doubt my barrel is going to get anywhere near steels curie point.

@freemo

Yeah, I think it would slow it down whether it attracted or repelled because it would be
perpendicular to the direction of travel. It wouldn't be like a railgun that pushes the projectile forward.

@peterwhisker @peterdrake @drewfer

@Pat

The force due to the magnetic field developed is **always** opposite the direction the metal is moving and perportional to the velocity of the metal (assuming a fixed magnetic field). So it will always have the effect of slowing down the metal, it will never cause the metal to move backwards.

@peterwhisker @peterdrake @drewfer

@freemo @Pat @peterwhisker @peterdrake @drewfer

Does repeated heating below Curie point have any effect?

@robryk

No but sorta... If you raise the temperute to a certain point below the curie point but near it, then the magnetic susceptibility will go down. Near the curie point it starts going down abruptly, its a non-linear response.

So what does that really mean. It means if you have a strong magnet it will partially loose its magnetic field near, but blow the curie point, but will retain some magnetization. By repeatidly cooling and heating the material to the same temperature it shouldnt do any further damage... this all assumes there is no external magnetic field.

@Pat @peterwhisker @peterdrake @drewfer

@freemo @Pat @peterwhisker @peterdrake @drewfer

Nit: if the field densite were not uniform, bullets from paramagnetic materials would be (slightly) pulled towards the area with the stronger field.