Waidsmannheil
You might get accurate data from the two European companies that I know producing 6x54MS i.e. Dorfner in Austria and Kynoch in the UK:
- Dorfner: www.waffen-dorfner.at or www.buechsenpatronen.at (I use their 8x56MS, which are excellent)
- Kynoch: www.kynochammunition.co.uk
Regards.
Louis