The Rodda I examined shows interesting markings
Proofed for cordite 60- 400 max
Caliber 404 ex
Underside of the barrel stamped 10.3mm and 74
Barrel stamped KRUPP STAHL
The markings have left me confused, the metric equivalent of the 404 NE would be 10.75 x 73. On another thread about Dons 404 mauser i also saw 10.3mm stamped, i guess this is the diameter across the lands but then how can this correspond to a groove diameter of 10.75 mm(.423 inches). Using modern .423 inch bullets on an undersize bore could be dangerous but Dons says that his mauser takes modern 404 ammo. So does this mean that a german stamp of 10.3 means a groove diameter of .423 inches??
Incidentally the German 10.75 x 68 mauser has a groove diameter of .423 inches but then the barrels are usually stamped 10.5 mm not 10.3mm
Also what does 74 instead of 73 imply??