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 (also known as a 44 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.