This British Bull Dog is marked Fredrick Gates San Francisco and he was located at No. 37 Sutter Street, San Francisco. This is .442 caliber Bull Dog and the mechanical function is very good crisp and tight and the bore is very good bright and shiny with strong rifling. It retains 65% original nickel finish and the serial number is 23802. .442 caliber British Bull Dog is a rare caliber, many more in .450 caliber were made.