My Remington M1917 does indeed have a .302-310 bore/groove diameter. It also has a .314 diameter throat but doesn't show excessive wear with a bore scope, so I assume it is as originally made. It would shoot jacketed .308 diameter bullets into pie-plate diameter groups at 50 yards. Using Sierra .311 150 grain PSPs it would shoot 1 1/2" at 100 yards. I now shoot Lyman's #314299 with exceptional accuracy. I also have a Winchester P14 with identical bore/groove measurements. A real tack driver for a .303 british rifle.