Explained: The U.S. Military's Love Affair With Shotguns

Kyle Mizokami

Security, America

Military shotguns still fill a niche that other firearms can't.

Key Point: Use of shotguns by the U.S. military has increased since the end of the Cold War and the rise of counter-terrorism operations.

One of the most popular civilian firearms, the shotgun, also has a role as a military weapon.

Originally designed as hunting weapons, many armies turn to shotguns for a variety of roles, including close combat and obstacle breaching. Although shotguns are too specialized to replace battle and assault rifles in infantry units, their utility will keep them in arsenals worldwide for the foreseeable future.

Shotguns are big bore long guns designed to hunt fast-moving birds and small game. In order to maximize hit potential, shotguns typically fire a cartridge filled with metal shot. Instead of a single bullet, shotguns eject tiny balls of shot in a set pattern covering a wider area. The most common shotguns, 12 gauge shotguns, have barrel diameters of 18.5-millimeters (as opposed to 5.56-millimeter for the M4A1 carbine) and pack one twelfth a pound of shot. Alternately, instead of shot pellets a shotgun can fire solid lead slugs.

Shotguns are not terribly suited to combat: shotgun shot has a maximum effective range of thirty yards, at which point velocity and predictable shot groupings quickly decline. Solid slugs are useful out to a maximum of one hundred yards. As a result shotguns are ineffective during combat in rolling terrain, with sight lines out to four hundred yards or more.

Combat, however, takes place over a variety of terrain and circumstances, some of which are very suited to shotguns. One of the first instances of shotguns used in warfare were so-called “trench” shotguns used during World War I. Shotguns could be fired down the length of a narrow trench, each pull of the trigger unleashing a hail of shot more likely to hit enemies than a single bullet from a bolt-action rifle.