Colts experimental carbine
A friend has asked me to help get information about this weapon. Thought being a colt you guys may have more luck than me researching it.
This is a Colt Experimental breech loading 58cal C/F (obsolete) Carbine of Martini type action with breech marked ????S PAT JUNE 11. 1867. Good strong action lock with safety catch and marked US COLTS Pt F.A. MFG CO HARTFORD CT 1863. 21 1/2"round barrel with worn but clear rifling, marked under barrel 4146 53. U on barrel band. Stock is sound with some small repairs and a lot of bench fire grip marks from test firing. A very rare and unusual gun, I can’t find any information on this Carbine. Any help would be appreciated