Follow the bouncing ball:
Oooops...lost the quotes. Oh well.
The 1851 model was a .36 caliber revolver. IIRC Colt made some experimental models in .41, but never marketed them. .36 was said to be "Navy Caliber," but that doesn't mean they were exclusive to the navy.
The 1860 was .44 caliber. .44 was said to be "Army," but again, that doesn't mean they were exclusive to the army.
Ok?
None of these percussion weapons will ever be re-adopted for current military service....unless the procurers develop a serious case of overwhelming insanity. So this whole discussion is immaterial. Not to mention wierd.