M18 Claymore mine

The M18A1 Claymore is a directional anti-personnel mine used by the U.S. military. Its inventor, Norman MacLeod, named the mine after a large Scottish medieval sword. Unlike a conventional land mine, the Claymore is command-detonated and directional, meaning it is fired by remote-control and shoots a pattern of metal balls into the kill zone like a shotgun.

The Claymore fires steel balls, out to about 100 m (110 yd) within a 60° arc in front of the device. It is used primarily in ambushes and as an anti-infiltration device against enemy infantry. It is also used against unarmored vehicles.

Many countries have developed and use mines like the Claymore. Examples include former Soviet Union models MON-50, MON-90,MON-100, MON-200, MRUD (Serbia), MAPED F1 (France), and Mini MS-803 (South Africa).

The M18A1 Claymore mine has a horizontally convex green plastic case (inert training versions are blue). The shape was developed through experimentation to deliver the optimum distribution of fragments at 50 m (55 yd) range. The case has the words "Front Toward Enemy" embossed on the front of the mine. A simple open sight on the top surface allows for aiming the mine. Two pairs of scissor legs attached to the bottom support the mine and allow it to be aimed vertically. On both sides of the sight are fuse wells set at 45 degrees.

Internally the mine contains a layer of C-4 explosive behind a matrix of about seven hundred 18-inch-diameter (3.2 mm) steel balls (about as big as #4 birdshot) set into an epoxy resin.

When the M18A1 is detonated, the explosion drives the matrix forward, out of the mine at a velocity of 1,200 m/s (3,937 ft/s), at the same time breaking it into individual fragments. The steel balls are projected in a 60° fan-shaped pattern that is 6.5 feet high and 50 m (55 yd) wide at a range of 50 m (55 yd). The force of the explosion deforms the relatively soft steel balls into a shape similar to a .22 rimfire projectile. These fragments are moderately effective up to a range of 100 m (110 yd), with a hit probability of around 10% on a prone man-sized 1.3-square-foot (0.12 m2) target. The fragments can travel up to 250 m (270 yd). The optimum effective range is 50 m (55 yd), at which the optimal balance is achieved between lethality and area coverage, with a hit probability of 30% on a man-sized target.

Weight 3.5 lb
Length 216 mm
Width 38 mm
Height 124 mm
Caliber 1/8 inch steel balls, 700 per unit
Muzzle velocity 3,995 ft/s (1,200 m/s)
Effective range 50 m
Maximum range 250 m
Sights Peep sight on early models, later a knife edge sight
Filling C-4
Filling weight 680 g
M4 Blasting Cap Assembly


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