"1851 U.S. Marshall .44 cal Revolver This is a reproduction of the revolver designed for official issue by the U.S. marshalls in 1851." Keith, I can't find anything to verify the statement by Traditions, either. The US Marshals' museum site shows an 1851 Navy as the only percussion revolver pictured. No mention of the so-called "US Marshall" pistol is made on their history page. The only change in caliber of a Colt production pistol was the use of the 1849 pocket .31 caliber frame to create a .36 caliber version by using the rebated cylinder first used in issuing the 1860 Army using the 1851 Navy frame. This latter was not a change, but creation of a totally new pistol. During this period, .44 caliber was considered "Army size', while .36 caliber was considered "Navy size". Guns of this period by any manufaturer in .44 were "Army", while those in .36 were "Navy". I suspect Traditions has created something not made back in the day. Stan