AGS‑40 Balkan is a Russian 40 mm caseless automatic grenade launcher and successor to AGS-17 and AGS-30, introduced and adopted by the Russian military.

Caseless ammunition (CL), or caseless cartridge, is a configuration of weapon-cartridge that eliminates the cartridge case that typically holds the primer, propellant and projectile together as a unit. Instead, the propellant and primer are fitted to the projectile in another way so that a cartridge case is not needed, for example inside or outside the projectile depending on configuration.