CWMill,
On 16/05/05, under the heading of Information Help, you posted photos of a best quality, German SxS rifle, by JJ Reeb, of Bonn, which you say you own. This rifle is chambered for the 8mm/.30-40 Krag which, for all intents and puposes is, ballistically, the twin of the .303 British. I'm puzzled as to why you would need to BUILD a .303.