This is a very fine example of an extremely rare Greene carbine, manufactured by Massachusetts Arms Co. circa 1855-1857 with a total production of only about 300. A majority of these carbines were manufactured with a 22 inch barrel, 54 caliber and had a brown finished barrel, blue receiver and casehardened lock and breech tang. All Greene carbines were equipped with the Maynard tape primer. This carbine has a 26 inch barrel chambered in 45 caliber and is finished in the very rare tin finish. A few were known to have been manufactured with the longer barrel, tin finish and smaller caliber. On page 31 of the book "Civil War Carbines Vol II" by McAulay he mentions that a few American Greene carbines were made with the 26 inch 45 caliber barrel, and finished in either tin or nickel. 200 of these carbines were delivered to fill a U.S. contract in March of 1856. Of the 200, 170 were sent out west and issued to the 1st Cavalry for field testing and carried on the Cheyenne Expedition in May of 1857. Most of the remaining carbines were sent to Florida for field trials and the small quantity remaining in U.S. arsenals at the outbreak of the Civil War were issued to the 6th Ohio cavalry. These carbines have a unique breech loading system. There is a set of two triggers, the front trigger releases the barrel that is turned to the left 1/4 turn. The barrel then is pulled forward and rotated to the right for loading and unloading. The upper tang is marked "GREENE'S PATENT/JUNE 27. 1854", the lock plate is marked "MASS ARMS CO./CHICOPEE FALLS" and the primer lid is marked "MAYNARD'S PATENT/SEP. 22. 1845". The serial number "5" is marked on the barrel under the rear sight and on the rear sight base. The barrel is equipped with a dovetailed blade front sight and folding ladder rear sight absent of any graduation markings. All surfaces had the tin finish including the brass patch box and buttplate. Mounted with a smooth straight grip stock.