40 mm grenades are used by grenade launchers in service with many armed forces.
There are two main types in service with NATO countries: the 40×46mm which is a low-velocity round used in hand-held grenade launchers; and the high-velocity 40×53mm, used in mounted and crew-served weapons.
The cartridges are not interchangeable.
Both 40 mm cartridges use the High-Low Propulsion System.
The less powerful 40×46mm is used in hand-held weapons.
The more powerful 40×53mm is used in automatic grenade launchers mounted on tripods, vehicles or helicopters.
In these roles, the rounds are linked together with a metallic disintegrating-link belt.