Introduced circa 1875. Breechblock utilizes the John Marlin innovation of reversible firing pin allowing for use of both rim and centerfire cartridges. Retains the distinguishing feature of the external extractor lever. Blade front and folding two leaf rear sights on a barrel numbered to the gun and marked "No44" at the breech. The left side of the frame is marked "MERRIMACK ARMS & MFG. Co. / NEWBURYPORT MASS." and "BALLARD'S PATENT / NOV. 5, 1861", with the 1864 patent date on the left side of the hammer spur. Smooth forearm and straight grip stock with crescent buttplate.

Fine. The barrel retains 70% original blue finish with the balance a smooth gray patina. The frame, hammer, buttplate and lever retain traces of original case colors and the breechblock retains 75% original case colors, otherwise faded to a silver-gray. The varnished wood is fine with some minor dings, scratches, and pressure marks (more numerous on the forearm), with most of the varnish remaining.