A new compact, lightweight weapon will stop a target in their tracks from a hundred meters away without harming them. Nicknamed the Pogojet, it's a radical less-than-lethal design from Jeffrey Widder, senior research scientist at Battelle Memorial Institute in Ohio.

The Pogojet —whose official name is the Caseless Telescoping Less-lethal System—is unique in that the propellant burns inside the round, pushing on a piston that propels it forward. The action resembles a pogo stick, hence the name. Once the piston reaches its full extent, the exhaust gases can be vented sideways, so the round continues forward at the same speed, or directed through holes in the base of the round like rocket exhaust to give as much extra kick as required. This is the 'jet' aspect of the Pogojet, which Widder compares to the old 1960s Gyrojet rocket pistol.

It's a clever design meant to get around a pesky problem. Conventional wisdom says that the non-lethal rounds used to stun suspects need to be big, soft, and slow. Think of the bean bag rounds fired from police shotguns, the 40mm sponge grenades used by the military, and traditional "rubber bullets." Their low velocity gives them a shorter range than a thrown rock—a serious disadvantage when facing rioters.

The other challenge with less-lethal impact weapons is balancing effectiveness with safety. A round that travels slowly enough to be safe at point-blank range is ineffective at long range. Increase the muzzle velocity to knock down a target further away and the weapon becomes potentially deadly when used up close.

http://www.popularmechanics.com/military/weapons/a18812/pogojet-non-lethal-gun/