Manufactured in 1846 by N.P. Ames of Springfield, Massachusetts and subsequently altered for paper cartridge use in 1861 by having the loading aperture enlarged to oval shape and rifling the bore. The vast majority of these carbines were made for the U.S. Navy and they were the only "mule ear" type arm that was officially accepted by U.S. armed forces. The lock is marked "WM JENKS" at the rear and "N.P. AMES/SPRINGFIELD/MASS" behind the hammer, and "WM JENKS" followed by "USN/RC/P/1846" on top of the breech end of the barrel. The left rear barrel flat and the lower tang are marked with the letter "R". The front sight is integral to the front barrel band and the rear sight is a groove on top of the breechblock. Oval loading aperture, brass barrel bands, trigger guard and buttplate with a sling ring mounted on the rear of the trigger guard plate. Brown barrel, and casehardened breechblock and frame. Mounted with a smooth full walnut straight grip stock absent of any cartouches.

Fair. The barrel has barrel has a mottled silver gray patina with scattered light pitting. The breechblock, hammer and lock have a smooth dark patina. The rear barrel band screw is stripped. The barrel bands and buttplate have an aged patina. The trigger guard has been repaired and the crack is still visible on the inside. The stock remains good with some scattered dings and dents. The markings are clear. Mechanically fine.