Hauptjäger,

I only know people here who can build guns or chamber and screw in New Barrels.
Barrel blanks in 9.3 and Chambered Barrels are sold by quite a few manufacturers - especially in the US.

Would suggest buy a Chambered barrel - I can't see any point in having to buy a chambering Reamer

Relaoding Dies from Huntington's, CH4D + others
Brass from Bell, Horneber, RWS (if you can find any)

I would suggest using M98 Action or a Win Mod 70 - however for a DGR I tend to prefer
CRF M98's or equivalent.

If you need more info, post again and I'll do some checking.

500 Nitro

PS - "to a point one can never have too much horsepower" - I totally agree - .500 calibre and above Anyday !!!