The US Government rejected the claims, and threatened reprisals in kind if any US troops were executed for possession of a shotgun. The shotguns elicited a diplomatic protest from the German government, claiming the shotguns caused excessive injury, and that any troops found in possession of them would be subject to execution. When fighting within a trench, the shorter shotgun could be rapidly turned and fired in both directions along the trench axis. The M1897 and M1912 also could be slam fired: the weapon having no trigger disconnector, shells could be fired one after the other simply by working the slide if the trigger was held down, though in the heat of combat one could easily short-stroke the weapon and jam it. The trench gun, as it was called, was a short-barreled pump action shotgun loaded with 6 rounds containing antimony hardened 00 buckshot, and equipped with a bayonet. The development of the repeating pump-action shotguns in the 1890s led to their use by the US Marines in the Philippines insurrections and by General 'Black Jack' Pershing's pursuit of Pancho Villa, and 'riot' shotguns quickly gained favor with civilian police units, but the modern concept of the combat shotgun was fully developed by the American Expeditionary Forces during World War I. Buck and ball loads were used by both sides of the American Civil War, often by cavalry units. However, buck and ball worked as well or better in standard or even rifled muskets. Fowling pieces were commonly used by militias, for example during the Texas Revolution. The disadvantage of this load was that the buckshot did not cause as severe wounds at longer ranges, and contemporary accounts show many of the British wounded recovering quickly as they had been struck by the buckshot rather than the ball. The advantage of this loading was that it had a greater chance of hitting the enemy, thus taking wounded soldiers out of a fight.

The buck and ball load was used extensively by Americans at the Battle of New Orleans in 1814 and was partially responsible for the disparate casualty rates between American and British forces. As use of the blunderbuss declined, the United States military began loading smaller lead shot ( buckshot) in combination with their larger bullets, a combination known as ' buck and ball'. Invented in the 16th century by the Dutch, the blunderbuss was used through the 18th century in warfare by British, Austrian, Spanish (like the Escopeteros Voluntarios de Cadiz, formed in 1804 or the Compañía de Escopeteros de las Salinas, among others) and Prussian regiments, as well as in the American colonies. While the sporting shotgun traces its ancestry back to the fowling piece, which was a refinement of the smoothbore musket, the combat shotgun bears more kinship to the shorter blunderbuss. Confederate cavalryman with muzzle-loading shotgun

Fallout 4 shotgun slugs