I have a Spencer 1865 (Burnside) .56-50 cal. with the serial number 33387. It is in really good condition. Markings on the stock indicate that it was returned to the armory twice. I have been told that the carbines with serial numbers in that range were issued to the 19th NY Vol. Cav. and to the 3rd Michigan Vol. Cav. I am trying to find out when it may have been issued, etc. Any information will be greatly appreciated.