Designed by Gilbert Smith, the production of this breech loading percussion carbine was almost entirely consumed by government contracts. Standard markings on the left side of the frame, "MANUFACTURED BY/AM'N M'CH'N. WKS/SPRINGFIELD MASS", agents' names "ADDRESS/POULTNEY & TRIMBLE/BALTIMORE U.S.A." and "SMITH'S PATENT/JUNE 23, 1857". The left rear barrel flat has the U.S. Government inspector's initials "LFR". Equipped with a blade front sight (replacement) and folding leaf rear sight absent of yard markings. Breech loading action with barrel release latch inside the trigger guard, freeing the barrel to pivot downward. Casehardened hammer and action with a saddle ring and bar mounted on the left side of the frame. Mounted with a smooth forearm and straight grip walnut stock with a steel buttplate, with a script letter cartouche stamped on the left side of the stock wrist.