special pepper spray ammunition based on paintball technology, consisting of a gelatin capsule filled with the riot control agent. The guns use compressed gas and provide semiautomatic fire, and the pepperballs act just like paintballs, fracturing on impact and splattering the chemical agent on impact. These can be used for direct fire, to break the balls on the target, or indirect fire, breaking near the target and spraying the agent into the target's vicinity. Police have been known to use paintball guns loaded with paint projectiles, to mark particular rioters so that police can easily identify and arrest them later. Some weapons discharge teargas as a solution in water. Legal issues Large-bore launchers are classified as firearms in most countries. Shotguns intended for riot use are semi-automatic shotguns subject to relevant regulations. Riot control ammunition may be restricted in various jurisdictions, to a lesser or greater degree than normal shotgun shells. United States In the U.S. large-bore launchers are subject to BATFE regulations. Since firearms over .50 caliber (12.7 mm) with rifled barrels are considered destructive devices under the National Firearms Act, only smoothbore riot guns may be sold to civilians without an NFA permit; a common form found on the civilian market are M203 grenade launcher replicas, which can be used to fire 37 mm practice rounds. The 40 mm guns are usually rifled, and may fire 40 mm grenades; explosive grenades rely on the spin both for stabilization and for arming the fuze. Lethality Riot guns have been documented to be lethal in some cases, with the use of an FN 303 by the Boston Police Department in October 2004 resulting in the fatal shooting of Victoria Snelgrove being one such incident. Types References External links Image of one-shot teargas grenade gun How Stuff Works page on riot control: image of single-shot 40 mm riot gun image of 6-shot 40 mm riot gun image of looking into end of cylinder image of 40 mm riot cartridges Firearms Non-lethal firearms Police weapons Gun, Riot