designed several automatic caseless 40 mm grenade launcher systems based on their own caseless ammunition weapon design. Unlike common caseless ammunition and their weapon systems the Metal Storm design lacked a feeding magazine and instead stacked the projectiles in front of each other in the barrel with the propellant in between the projectiles. The system lacked moving parts and the propellant was electronically primed, allowing for rates of fire up to one million rounds per minute. The 40 mm grenades used in the systems were off the shelf existing warheads converted to function in the design. See also 35 mm grenade 40×46mmSR Hellhound United States 40 mm grenades Notes References External links Milkor Worldwide 40mm Low-Velocity Grenades Defense Review overview of Mk 47 Mod 0 'Striker' 40mm Grenade Machine Gun Defense Review overview of Corner Shot 40 personal grenade launcher Defense Review overview of Penn Arms PGL65-40 'Fourkiller Tactical Model' 40 mm Multiple Grenade Launcher Penn Arms data page for PGL65-40 6-Shot Grenade Launcher Defense Review overview of Metal Storm 40mm Weapon System Future Weapons: MEI Mercury 40MM Grenade Grenades Ammunition Projectiles Military cartridges Paramilitary cartridges Large-caliber cartridges