The M40 High Explosive Dual Purpose (HEDP) Grenade is a type of high explosive fragmentation grenade manufactured by Armat Battlefield Systems. It was predominantly employed by the United States Colonial Marine Corps.
The M40 is primarily designed to be fired from the U1 Grenade Launcher, although it can also double as a hand grenade. The cartridge consists of two main sections — a rimmed, separating base and a metal casing topped with a red plastic identifying cap. When fired from a U1, the base propels the casing from the grenade launcher's barrel with a muzzle velocity of around 78 m/s. The grenade round has an effective range of 400 m, and an accurate range of around 180 m. The projectile itself contains notched steel wire wrapped around a Composition B15 explosive core, which spreads more than 300 metal fragments over a casualty radius of 5 m upon detonation.
Despite its main purpose as a launched projectile, the M40 can be employed as a hand-thrown grenade by flipping off the red plastic cap and depressing the button beneath. This will trigger a three second fuse, after which the round will detonate.
Behind the ScenesEdit
The 30mm grenade props seen in Aliens were constructed from 12 gauge aluminum snap caps (an inert cartridge simulator made to the same external dimensions as a live round, used for training purposes); the fact 12 gauge rounds are actually only 18.53 mm in diameter is simply ignored in the film. The snap caps were embellished with additional machining cuts made for cosmetic appearances, a push button on the top, and a colored plastic cap, which was red for the M40 high explosive rounds seen on film.
- In real life, the acronym HEDP is an alternate designation for high explosive anti-tank (HEAT) warheads, which use an explosive shaped charge to penetrate solid vehicle armour. In the case of the M40, the "dual purpose" moniker seems to refer to the fact the grenade can either be launched from a U1 or hand thrown.
- ↑ 1.0 1.1 Aliens: Colonial Marines [Microsoft Windows, PlayStation 3, Xbox 360]. Gearbox Software.
- ↑ 2.0 2.1 2.2 Lee Brimmicombe-Wood (1996). Aliens: Colonial Marines Technical Manual. HarperPrism, 15.
- ↑ James Cameron, Gale Anne Hurd, Gordon Carroll, David Giler, Walter Hill, Stan Winston. Superior Firepower: The Making of 'Aliens' [DVD]. 20th Century Fox.