Quoted TextThe Germans measured the O.D. of the projectile differently (actually bore I.D.) than the Soviets. One measured from the diameter of the lands, while the other went by the diameter of the grooves . . . I seriously doubt there's much difference between the two bores.
Two statements here that need to be corrected:
> Both the Soviets and the Germans measured artillery in the same way.
> The 76.2mm Russian and 7.5cm German bores were different.
Both of these questions were resolved earlier and are apparent from manual illustrations referenced by Philipp. The bourrelet of a German 7.5cm projectile was 74.85mm in diameter and the projectile for the Russian gun was 76.1mm. The bourrelet diameter is a very close fit to the bore diameter of the tube, so the bourrelet diameter is effectively the same as the bore size.
if you'd ever shot a cannon, you'd know that the round has to slip into the bore till the driving band seats into the rifling. There must be some clearance to get the driving band to seat. Also the rifling would be trashed after one round