This awesome 'trench broom' terrified Germans in both World Wars

A single weapon used predominantly in World War I and with a limited deployment in World War II was so effective and so terrifying that Germany lodged a diplomatic protest against its use by American forces. It wasn't the flamethrower or the machine gun. It was shotguns, especially the Winchester Models 1897 and 1912.

The two shotguns were first entered into combat after America realized how brutal trench warfare really was. The soldiers and Marines serving on the Western Front needed a way to clear attackers from the American trenches as well as to quickly clear defenders from enemy trenches during assaults.

The spread of a shotgun was perfect for this mission, but the Americans didn't stop at just buying off-the-shelf weapons. The War Department contracted for standard, trench, and riot versions of most shotguns.

Standard shotguns were civilian versions of the weapon, often with a sling added for easy carrying. Riot guns were similar but with shorter barrels. The most heavily modified versions were the trench guns which featured shorter barrels — usually 20 inches or shorter, heat shields, and bayonet lugs.

The Model 97 quickly became one of the most popular shotguns issued, partially because of how well it stood up to the rigorous conditions on the Western Front. Operators could quickly clean mud and water from the weapons and get them ready to fire after a mishap, and the weapon continued to function even if it was dropped or slammed against trenchworks.