N146 groove diameters were usually .366" I am told - perhaps I used the wrong word, "bore" - sorry. The bore is .358".

Yes - I meant just that when I stated tighter tolerances - meaning without the odd headspace problems the M46's had. Normally a Euro. rifle would not have headspace problems. The 9.3x57 was never entered into the CIP laws, thus, there are not locked in stone measurements. That hundreds of these rifles are being used today here in NA, speaks well for them.

My MN46, with a measured .019" headspace was not a problem as I first opened the cases up straight, then sized them for a "crush" fit, making headspace tighter than "0". This only has to be done once.

The case is only 'tight' the first time it is chambered. Once fired, they are form fitted and then shrink the .001" or so for easy extraction.

It is important that when sizing, only size as much of the case as in necessary - same as with any round. Do not push the shoulders back when they are sized.

Throats are not a problem, even if a bit long. My rifle puts everything from 225gr. re-sized Hornady's, then all of the various 9.3 bullets and up to resized 300gr. Hornady's, into from 3/4" groups to 1 1/2".