Can a powerful magnet curve the path of a bullet?
We sell some incredibly powerful magnets. If a really powerful magnet was placed near the path of a bullet, could it curve the bullet's path? Is it possible?
This question has been asked a number of times, both on television and the Internet. Mythbusters investigated it in episode 95, one of their James Bond specials. They fired a bullet above a series of magnets to see if they could alter the bullet’s path. Their test made a bullet tumble end over end, but didn’t change the path much at all.
There’s also some debate on the Internet about how Magneto stopped a bullet in the original X-men movie. Is it possible? What sort of energy would it need? It’s a little silly, debating the physics of a superhero movie, but interesting nonetheless.
Does a strong magnet placed very close to a bullet’s path curve it? Typically, no.
Most bullets aren’t ferromagnetic – they aren’t attracted to magnets. Bullets are usually made of lead, maybe with a copper jacket around them, neither of which sticks to a magnet.
The magnet might impart some force on the bullet via Eddy Currents. The same way a magnet falls slowly through a copper pipe, the magnetic field can induce tiny currents in the electrically conductive material, pushing it a little bit. The problem is that this is a tiny amount of force, exerted on the bullet for only a tiny period of time as it passes over a magnet.
In that Mythbusters episode, they showed how strong magnets didn’t quite curve a bullet’s path, but made it tumble. We suspect this was because eddy currents acted more on the bottom of the bullet, closer to the magnets where the field strength is greater. The direction the bullet tumbled is consistent with this theory.
Still, even this didn’t alter the path of the magnet. It still hit the target in the same spot.
Naturally, we wanted to demonstrate some situation where a magnet could really change the bullet’s path. So we stacked the odds in our favor! To make the bullet curving magnet possible:
We shot a steel BB instead of a lead bullet. This helps because steel is attracted to magnets. Plus, the lighter mass of the BB means we’re fighting less momentum.
We shot the BB from a low powered, pump-action air gun. The lower projectile velocity means it’s easier to change the path.
We also only pumped the gun once, instead of the recommended 3-5 times. The lower air pressure made the initial bullet velocity slower, reducing its momentum.
The test setup is fairly straightforward. For the baseline, we aimed the air rifle at a target several feet away.
After recording the path of the bullet, we made the same shot with a powerful 3” diameter x 1.5” thick, grade N52 DZ0X8-N52 magnet just below the bullet’s path. Would we see a difference between the two shots?
The video below shows some great high-speed footage of our results. The magnet was able to alter the path of the BB!
As they say, “Don’t try this at home!”