Sportclay, the letter code used is an abbreviation formed from the initials of the Swiss French decimal numbers (i.e., QSX = quarante-six = 1946).
Thank you very much!
Sportclay, the label says Teilmantel, which means semi-jacketed or soft-nose.
105 is the Swiss catalogue number (Switzerland had a powder and ammunition monopoly). I only have data for the later (about 1951) No. 185, which fired a 13.1 g bullet at 680 m/s from a 680 mm barrel.
Must be the half jacket is inside the case. The exposed lead portion is a very hard lead alloy. Thank you for the info on the projectile weight and vel.