1929 is the date of mfg. of my M46 rifle.

In stating the lack of CIP laws/rules regarding this round, I was repeating what was noted by some Swede rifle collectors on a Swedish Rifle Forum I belonged to some time ago. They noted the huge variation in chamber sizes was due to the lack of standards on this round. That this lack of standards was particular to an 'era' I now understood - thank you - as I understand most M98's chambered in this round have what appear to be normal chambers.

The members of that forum with some experience in loading seem to either use 9.3x57 Privi brass, form shorten and neck turn '06 cases, or simply neck up 8x57's to .375 then down to .366" forming a tiny false shoulder as the do this. That small false shoulder, I felt, was not sufficient to hold the case against the primer blow and some stretch occurs above the web, 3/8" above the rim. Thus, I neck them straight - it takes no longer to do this and the formed case then looks almost identical to a fire formed case.

Those who simply neck up 8x57's to hold a .366" bullet usually find from .004" to .010" primer protrusion with Norma-like loads, which shows a headspace problem of varying magnitude.

On that forum, I/we have not seen any rifles with 'short' chambers which needed 8x58 shoulders pushed back - which is a very simple thing to do.

Incidently, my rifle's bore was noted as being slighlty dark, but shootable by the importer - Tradeexcanada. I cleaned it properly after receiving it and while not in 'new' condition, it is quite excellent, albeit oversize at .370" groove dia., but it does shoot sub - moa with ALL bullet weights from 225gr. to 300gr.