This is a documented example of a U.S. military ammunition test pistol and "V" block that would have been used in a Frankford rest. The receiver was manufactured in late 1918 and has been fitted with a 5 inch heavy round barrel with a large cylindrical lead weight that is secured between two steel collars with locking screws that are connected with a rectangular bar on the left side. The bolt is stamped "W L/3" on the top flat of the curved bolt knob. It has a walnut stock with a pistol grip. It is described and photographed on page 227 of "The Springfield 1903 Rifles" by Brophy. With a steel "V" block rest which is described as a "Frankford (arsenal) Rest" in Brophy's book.