40 mm grenade (also styled 40mm grenade) is a generic class-name for grenade launcher ammunition (subsonic shells) in caliber. The generic name stems from the fact that several countries have developed or adopted grenade launchers in 40 mm caliber. This is a general collection of the world's many different "40 mm grenades". NATO NATO currently uses three standardized 40 mm grenade families: 40 mm low velocity (LV), 40 mm medium velocity (MV), and 40 mm high velocity (HV). Low- and medium-velocity cartridges are used for different hand-held grenade launchers, while the high-velocity cartridge is used for automatic grenade launchers. 40×46 mm LV (40 mm low velocity) 40×46 mm LV (low velocity) is a NATO-standard high–low grenade launcher cartridge meant for hand-held grenade launchers, such as the M79, M203, Milkor MGL, and Heckler & Koch AG36. The propellant has low pressure and gives the projectile an average velocity of depending on the ammunition type. 40 mm low-velocity ammunition types (NATO) Besides combat ammo there also exists crowd control ammunition like sponge grenades. 40 mm low-velocity ammunition types (Sweden) Sweden currently operates the M203 grenade launcher (designated in Sweden) and thus uses the 40 mm low-velocity cartridge. Going against Swedish military tradition, the 40 mm low-velocity cartridge currently lacks a specified indigenous designation in Swedish service. Instead only the projectile types have designations. Currently these projectile types can be found in Swedish service manuals. Mockups and inert types also exist for loading exercises and educational purposes. 40 mm low-velocity ammunition types (Romania) Romanian arms producer ROMARM has made a version of their 40 mm rifle-mounted grenade launcher AG-40 chambered in 40×46 mm NATO (then designated AG-40PN). Production of Romanian 40 mm low-velocity ammunition is handled by the arms factory , a subsidiary of ROMARM. The projectiles seem to be of Romanian origin based on available information. SAGM fuze The United States Army Armament Research, Development and Engineering Center (ARDEC) began development of a 40 mm smart airburst fuze (proximity fuze) in 2011 to improve the ability of grenade launchers like the M203 and M320 to engage targets in defilade. Called small arms grenade munitions (SAGMs), they double the lethality of the standard M433 grenade round by adding a small "smart" fuze sensor that detonates in the air to hit targets in cover or behind obstacles. The airburst function is similar to the XM25 CDTE, which has an onboard laser system to determine