3.2-inch gun M1897

The 3.2-inch gun M1897 (81 mm), with its predecessors the M1885 and M1890, was the U.S. Army's first steel, rifled, breech loading field gun. It was the Army's primary field artillery piece in the Spanish–American War, Philippine–American War, and Boxer Rebellion from 1898 to 1902. This series of weapons was designed to provide a modern alternative to breech loading conversions of the Civil War-era 3-inch Ordnance rifle. It was constructed of steel and was of built-up construction with a central rifled tube, and reinforcing hoops from the trunnions to the breech. Its steel was stronger than the wrought iron of preceding weapons. The guns had an interrupted screw breech with either a de Bange plastic obturator or (on the earlier modifications) a conceptually similar design by Spaniard Luis Freyre y Góngora with a metallic ring, and fired separate-loading, bagged charges and projectiles. The projectiles weighed approximately and common, shrapnel, or canister types available. The M1885 and M1890 used black powder when first introduced, but the M1897 was redesigned for smokeless powder; the M1890 weapons were then modified for smokeless powder and re-designated M1897s. In the Spanish–American War, difficulties were encountered in ramping up production of smokeless powder, so the M1885 and M1890 weapons were deployed to use the available black powder. The M1890 was a simplification of the M1885, with the barrel made from two forgings instead of eight. The guns had a box trail carriage built from bolted steel plates with two large wooden spoked wheels. The guns did not have a recoil mechanism or a gun shield but the carriage's wheel brakes provided some recoil absorption. Due to its low angle of elevation +20° it was a direct fire weapon. For transport, the gun was attached to a limber for towing by a horse team and there were seats attached to the axle of the carriage for the crew. The limber also had seats for crew members plus ammunition and supplies. This weapon was the workhorse light artillery piece of the Spanish–American War and the Philippine–American War from 1898 to 1902.