The Mecar M72 is a

fragmentation Fragmentation or fragmented may refer to: Computers * Fragmentation (computing), a phenomenon of computer storage * File system fragmentation, the tendency of a file system to lay out the contents of files non-continuously * Fragmented distributi ...

hand grenade A grenade is an explosive weapon typically thrown by hand (also called hand grenade), but can also refer to a shell (explosive projectile) shot from the muzzle of a rifle (as a rifle grenade) or a grenade launcher. A modern hand grenade genera ...

used by the Belgian

military A military, also known collectively as armed forces, is a heavily armed, highly organized force primarily intended for warfare. It is typically authorized and maintained by a sovereign state, with its members identifiable by their distinct ...

. It was designed by Belgian company

PRB The retinoblastoma protein (protein name abbreviated pRb; gene name abbreviated ''Rb'', ''RB'' or ''RB1'') is a proto-oncogenic tumor suppressor protein that is dysfunctional in several major cancers. One function of pRb is to prevent excessive ...

, with

Mecar Mecar is a Belgian weapon and ammunition manufacturing company headquartered in Petit-Roeulx-lez-Nivelles, Hainaut Province. Mecar is responsible for creating weapons ranging from grenades to lightweight anti-tank cannons. The company was establishe ...

taking over production after PRB closed. Made by PRB it was known both as the PRB 423 and the M72. The M72 grenade has an egg shaped body fitted with an internal notched steel wire fragmentation coil. The grenade weighs in total, with an explosive load of

Composition B Composition B, colloquially Comp B, is an explosive consisting of castable mixtures of RDX and TNT. It is used as the main explosive filling in artillery projectiles, rockets, land mines, hand grenades and various other munitions. It was also use ...

. Its

fuze In military munitions, a fuze (sometimes fuse) is the part of the device that initiates function. In some applications, such as torpedoes, a fuze may be identified by function as the exploder. The relative complexity of even the earliest fuze d ...

delays detonation 4 seconds after the spoon is released. The inner tube explosion causes the main explosive load to detonate, which produces 900 shards of

, each weighing around . The top of the body around the fuse thread was filled with 33 0.1 g metal ball bearings and a further 22 are placed inside the bottom closing plug. The grenade has a lethal radius of , an injury radius of , but beyond radius the risk of injury is minimal. An untrained soldier could normally throw the grenade , making it safe to use as on offensive grenade, as well as a defensive grenade. A re-usable practice grenade was made with a solid Aluminium body. Known as the M73, the grenade body vented gases from a 13mm hole running from the fuse carrier thread to the bottom of the grenade. This grenade uses a four second delay fuse identical in all respects to the M72 fuse except the detonator has been replaced by a deflagrator, which produces noise and smoke. A very similar drill practice grenade was made than had a 9 mm through hole. This would only mount the M73A1 Practice fuze (with no charge for drill purposes) The deflagrator fuse is too large to fit the drill grenade, but either drill fuse or deflagrator fuse will fit the practice grenade. PRB made a similar Offensive grenade known as the PRB 446. It did not have the fragmentation coil or ball bearings but carried a greater explosive load ( grams of cast TNT). It was externally the same as the PRB 423 apart from the brown body colour and the different identification marks printed on the grenade.

References

M72 at Milpedia
Mecar Grenades of Belgium {{Grenade-stub