.69 caliber. 42" round barrel secured by three flat, spring retained bands. NSN. Freckled traces of National Armory Brown finish, now essentially bright, iron furniture, smooth walnut stock. Single shot muzzleloading percussion altered US military musket. Lock marked with a {SPREAD-WINGED EAGLE}/US forward of the hammer and in three vertical lines at the tail: SPRING/FIELD/1827. Hewes & Phillips added patent breech dated 1862 with H&P mark on face of bolster. Counterpane with no visible cartouches. Altered to percussion by the firm of Hewes & Phillips of Newark, NJ and additionally modified by adding a US pattern of 1858 3-leaf rear sight at the breech but without rifling the bores. Approximately 12,000 guns were so altered with patent breeches, and long range rear sights without rifled bores, primarily for the US government. Musket retains both original sling swivels, the H&P added, tall iron front sight on the upper band, the small socket bayonet mounting lug on the top of the barrel near the muzzle and a full-length original button head ramrod with good threads at the end.