I slugged both my No.1 and No.4 yesterday and found the "true" calibre of the barrels. The No.1 was bang on .311 but the No.4 was .315. So does anyone know of a manufacturer that makes a bullet between the .303 British and 8mm Mauser that would fit that barrel snugger? I know that Hornady's 174 Gr RN is .312 but is there anything closer? Thanks.