# Is a Centrifuge Rifle Feasible?

We have discussed the Railgun and the Coilgun, I'm fairly sure we've even talked once or twice about magnet guns. But could a centrifuge gun exist?

For those who do not know, a centrifuge rifle is exactly what it sounds like, at the pull of the first trigger the hollow, donut shaped barrel spins the bullets until they reach terminal velocity and then when the second trigger is pulled, the bullet fires out of the barrel. I see three obvious problems with this theoretical gun;

1. Ammunition, a centrifuge gun would be limited to spherical ammunition, and is likely to jam.
2. Munitions, a centrifuge gun would require a large battery and would need to be charged often.
3. Accuracy, a centrifuge gun would be at best inaccurate and at worst lethal to the wielder.

What can I do to make the centrifuge gun design feasible? would changes need to made?

• This is basically an electric sling. Start thinking from there, not from a rifle. A rifle refers to weapons with rifled barrels that spin stabilize the projectiles, anyway. – Ville Niemi Sep 15 '16 at 5:08
• According to wikipedia this has been attempted. It seems the main issue is accuracy. There even exists a modern patent for such a gun. – Mike Nichols Sep 15 '16 at 5:43
• Mythbusters Proof of Concept : youtube.com/watch?v=YKhLgPyymfU – JonSG Sep 15 '16 at 19:49
• Your barrel will wear far too fast for it to be useful – nzaman Sep 16 '16 at 6:33
• @MikeNichols I did not see it before, but that patent is owned by the person /company that made the video I refer to in my answer below. So that patent is about as useful as a papier-maché aircraft carrier. – MichaelK Aug 31 '17 at 12:21

# No, it is not feasible

A few years ago, this hoax/scam video was making the rounds. I did the math on the claims.

In short: this thing — in order to live up to the claims in the video — has the power requirements of a nuclear powered warship

And then I did not even begin to look at things like gyro forces, vibrations, losses, sound, etc... I was only looking at the projectiles.

Problems with it:

• Recoil. There will be recoil. Sir Isaac Newton cannot be fooled. To be precise what you will have is an unbalanced flywheel that will vibrate violently.
• Enormous gyro forces. The velocities the flywheel must move at means you have a huge disk spinning at Ludicrous Speed. You cannot turn that, meaning you can only aim in one plane.
• Enormous centrifugal forces. What do you think happens when the enemy scores a hit on that flywheel and it shatters? That is right: a claymore mine exploding right in your face.
• Power requirements. Already mentioned.
• Long start-up. It takes time to spin up the flywheel to any usable speeds.
• Poor ballistics. Such a weapon requires spherical ammunition to work. Spheres have the worst ballistics of all kinds of ammunition, resulting in poor accuracy and short range.

So to answer your question, what do you need to make this feasible? Answer: You need to break the laws of physics. The centrifuge gun is a bad idea, not matter how you slice, dice or chop it.

• You could deal with the unbalanced flywheel by including 2 projectiles and releasing one forward and one backward at the same time. This would also help to deal with keeping Sir Isaac Newton happy... just don't stand behind someone shooting. A typical Ultracentrifuge has to deal with some of the other problems. A disintegrating Ultracentrifuge disk is apparently interesting to see and by "see" I mean watching the armored casing jump into the air a foot or so is interesting as told to me by someone who saw it happen in a lab. If you can see the disk when it blows you die. – Murphy Sep 15 '16 at 12:35
• @Murphy Yeah it will keep Newton happy. It will not keep whoever is behind the shooter happy, and that is slightly more important :D As for more examples of what happens the rapidly spinning things go to pieces, search for videos of "blade off test" or "blade release test". – MichaelK Sep 15 '16 at 13:09
• @Sky Oh yes, RPGs and recoil-less rifles have that danger. The Swedish Carl-Gustav for instance (84mm, big back-blast) has the following procedure: shooter calls "Shot coming!"; the loader locks back, checks behind them; loader calls "Clear behind!"; and only then can the shooter loose the shot. However(!)... the range of that back blast is 10-15 meters at the most, with the lethal area being only about 5 meters. A bullet on the other hand... – MichaelK Sep 16 '16 at 13:05
• not matter how you slice, dice or chop it. - or rather, no matter how it slices, dices or chops you. – walrus Sep 1 '17 at 10:55
• @walrus In Soviet Russia.... gun shoot you! :D – MichaelK Sep 1 '17 at 10:59

You'll also have to factor in the gyroscopic forces of a rotating barrel. If you've ever played with spinning a bicycle wheel, you'll know that it resists leaving it's current axis of spin. This would make aiming the thing somewhat tricky.

However, a fixed turret with a stack of ten or so rotating barrels, now that's a whole different thing and would be decidedly deadly.

wouldn't this basically be a slingshot? Look at how slingshots work. Also disc throwing. Those are 2 examples from the real world that turn centrifugal force into forward momentum.

Ammunition - would probably need to be either spherical or disc shaped. But since your launch mechanism isn't chemical and you don't have a bullet, that shouldn't be a problem.

Munitions - For a non stationary gun, especially handheld, it's probably a lot more practical to go for something based on a different technology. The gun would probably require a lot of energy. But, compared to rail gun or coil gun, the power requirements would probably be comparable. If you want a stationary weapon(think tank, boat or something similar) you no longer have that much problems with power requirements, or accuracy(since a computer can accurately target it.

Accuracy. As already said, it would be difficult to target without tech, but computer release mechanism should be quite simple to use.

The only advantage i ca see for such a gun would be it's ability to hurl unstable material, since it gives its ammo a much slower starting speed than say a bullet.