The M1917 bayonet was originally designed to be used with the US M1917 Enfield .30 caliber rifle, as well as with the seven different U.S. trench shotguns. The blade is 17 inches (43.18 cm) long. The M1917 Enfield was the U.S. Version of the British P-14 rifle, and the bayonets used are identical, down to the double groove in the grips, used to differentiate the bayonets from the P-1907