In 1855, the U.S. Army adopted a series of muzzleloading weapons with various lengths of rifled barrels designed to use a standard .58 caliber round. The most widely used of these was the 40" barrel rifled musket, manufactured at both the Springfield and Harpers Ferry arsenals. It is possible that some of the Infantry companies garrisoning Fort Abercrombie prior to the Civil War were armed with the Model 1855 rifled musket.