The Napoleon 12 Pounder Bronze Field Gun Model 1857 had a 4.62 inch bore, a tube weight of 1225 pounds, a tube length of 66 inches, and a maximum range of 1660 yards. It was inspected by T.J.R. in 1863, identified as Thomas Jackson Rodman, a Union officer, and was U.S. stamped to show it had been tested and approved for use. It was manufactured in 1863 by Cyrus Alger and Co. of South Boston, Mass., with serial number 138 and foundry number 1207. Its charge was 2.5 pounds of black powder, and its ammunition included a 12 pound ball, spherical case, shell, and canister. Its muzzle velocity was 1485 FPS. Total manufacture was 1156 for the Union and 501 for the Confederate side, and its service record is unknown.