US Cartridge, 40mm Practice, M918
This cartridge is a target practice round designed to simulate the M430 Cartridge in appearance and ballistics. It is fired from the 40mm Grenade Machine Gun Mk 19 Mod 3. It is also used in the Cartridge, Subcaliber Ammunition, Training (CSAT), M970 to simulate the loading and firing of large caliber ammunition.
This cartridge is a fixed round of ammunition consisting of a one-piece steel projectile body which is fitted to a cartridge case assembly. An aluminum ogive, which contains a firing pin plate assembly, a cellular foam anticreep spring, and the standard M550 fuze escapement assembly is threaded to the projectile body An aluminum insert which contains a flash charge chamber is enclosed in the projectile body. A plastic container contains the flash charge chamber which contains one gram of flash charge composition. The projectile assembly is press-fitted into a cartridge case. The case is a hollow bichambered aluminum cylinder with a metal closing plug crimped into the open well of the propellant chamber cartridge base. The propellant in the chamber, which contains the propelling charge, has vent holes in the top and is sealed at the bottom by a closing plug. A percussion primer is crimped into the center opening in the closing plug. The propellant chamber acts as high pressure chamber, and the upper hollow cavity in the case acts as a low-pressure chamber.
Collaborative Ordnance Data Repository