The Ninety-Nine, A History of the Savage Model 99 Rifle, by Douglas Murray. 303-inch (7.7 mm)Pattern 1914 Enfield (P14) rifle (listed in British Service as Rifle No. 30, Model of 1917' is an American modification and production of the. Rifle serial number M1917 Enfield, the 'American Enfield', formally named ' United States Rifle, cal.