I am new to this forum and looking for anyone's expertise on this issue . I am considering purchasing a Colt Model 1851 Navy revolver . The serial number is 110,xxx . The address on the barrel is "Sam Colt New-York U.S. America" . From my research that would indicate a manufacture date of likely 1861 . However , it does not have the "36 cal" stamped anywhere near the left rear trigger guard . One article indicated this stamp was placed on these model Colts manufactured after 1860 , in order to distinguish them from the colt Army model . Has anyone run across this situation before ? Is my date estimate correct ? The gun matches all other written descriptions I have found , and all serial numbers are matching . Thanks for your help .