Launching non-metallic projectiles.

Kinda wondering, with an eye towards actually building a launcher, if it’d be possible to build some sort of device that can shoot a small, non-metal projectile without any moving parts?

Obviously a railgun will work with a metal object but how about something else? How about a projectile that is electrically conductive but not made of metal? I remember an old PS article on mass drivers which used plastic slugs.

In this case I’m thinking paintballs - .68 caliber, gelatin/plastic shell and thick liquid fill, maximum speed less than 100 meters per second. Not sure if they are in fact conductive but that may be solvable.

I want to have no (if possible) moving parts and avoid the use of compressed gas (Co2 or high pressure air, as in current paintball markers)

How about magnetohydrodynamic (MHD) propulsion.

Firstly the projectiles must contain a mobile electrolyte.

Parallel conductive plates on either side of the projectile cause movement of ions through the field. A huge magnetic field parallel to this uses a Lorentz force to propel the projectile parallel to the electric and magnetic fields.

The formula to calculate the force is F=IlxB, where I is the current, l is the length of the plates and B in the magnetic field strength.

Someone might be able to do the calculations, but for a 100 m/s projectile that is 10 cm long and 2 cm diameter, I reckon you would need a very big truck to carry the gun.

Uh, is there a reason you’re putting so very many restrictions on your launcher? Because moving parts and/or expanding gases are traditionally the ways to propel things, and they work really well. Is this for a science fiction story or something?

Given your limitations, I can think of only two things. The first is to use a metallic sabot that a magnetic accelerator could get a grip on. The second is to (somehow) put a massive static charge on your projectile, and then use an equally massive charge on the barrel to accelerate it (either repelling or attracting). Unless you’re willing to deal with some truly dangerous voltages though, I doubt you’re going to get a lot of velocity, and it’s gonna be hella complex to build. The necessary transformers and capacitors mean that it’s also likely to be pretty heavy. I don’t think this is going to be something you’re going to run around with in the woods, plinking away at your buddies.