The accompanying factory letter lists this musket as chambered in .45-70 caliber when received in the warehouse on September 8, 1892 and shipped the same day. The rifle has a 30-inch round barrel with full-length magazine and distinctive blued steel forearm cap. The barrel is secured by a single band and has a steel block front sight that serves as a mount for a socket bayonet and a military style folding leaf rear sight. Factory sling swivels are fitted to the barrel band and stock. The carbine style buttplate has a sliding brass trapdoor. The butt trap contains a five-piece steel cleaning rod. The top of the barrel is roll-stamped: "-< MANUFACTURED BY THE >-/-< WINCHESTER REPEATING ARMS CO. NEW HAVEN CONN US.A >-" in two lines between the barrel band and rear sight. The caliber "45-70" is roll-stamped on the top of the barrel between the rear sight and the receiver. "MODEL 1886" is roll-stamped on the upper tang. The 1884 and 1885 patent dates are roll-stamped on the lower tang behind the trigger. The serial number is roll-stamped in script numerals on the lower tang between the tang screws. The barrel, magazine, forearm cap, barrel band, rear sight, bolt, loading gate, trigger and sling swivels have a blue finish. The receiver, hammer, lever and carbine style buttplate are color casehardened. The receiver and buttplate have vivid case colors. The stock and forearm are straight grain, oil-finished American walnut. The Model 1866 Musket was made in smaller numbers than any other Model 1886 variation and is the rarest of the scarce Winchester lever action muskets.