Custard gun

The custard gun has a two-part cartridge containing two gel like materials instead of a magazine. The gel in the front is a custard, while the gel in the back is a propellant that can be electrically ignited.

The gels are extruded one at a time into the sealed firing chamber of the gun itself, first the propellant in the back, and then the custard in the front. A small circular sliding block ensures that the gels fill the firing chamber in a relatively uniform manner, and when the weapon is ready to fire, a second sliding block pushes the original block out of the way, and permits an opening to the bore of the gun.

Pulling the trigger produces a spark, either by way of a piezo, or a battery pack and spark plug, depending on whether you trust piezo igniters, or batteries less. The spark ignites the charge, and the force of the explosion causes the custard to act like a solid, upon which it is fired out of the gun in a single mass.

The gun can then be reloaded by extruding more charge and custard. The problem of semiautomatic firing should prove rather tricky, and would probably involve several separate firing chambers arranged into something like a revolver.

Reload time, and accuracy are likely to suck, and the ammo would probably split into shot-like globules while in flight, but the gel nature of the ammo makes the magazines far more compact than regular ammo, and greatly reduces identifying markings on spent rounds.

Depending on the exact nature of the custard, the device could fire a number of nonlethal rounds. Air resistance is likely to reduce the velocity on impact so that the material might not harden when it hits, and most custards are lighter, and more rubbery than lead.

Chemical agents may also be possible, although for the assasins out there I'm sure there will be some very dense easy to harden type of custard, which continues to function like a solid throughout it's flight, and on into the deeper body cavities of the unfortunate target.

Undoubtedly, this will become the ideal weapon for cop-killing. Just stick a jelly doughtnut by the corpse, and the coroners are left to conclude that the victim was a dangerously messy eater... Not that I or anyone I know would ever want to assasinate an officer.