The cartridge is 9x57 as halger stated. The 108.49 is , indeed, one of the marks often found on pre 1911 sporting 9.3 mm rifles( mostly rimmed). Mauser stamped the barrel with other markings which show specifics of the barrel's dimensions. The 8,85( they used a, instead of a .)is the bore(not groove or bullet) diameter. The 9,1 is the groove diameter. The 850 is the length of twist. These dimensions fit the 9x57. Also, the barrel is marked 9,0H. We call the cartridge 9x57 Mauser, but some think it was actually a Haenel cartridge, which could fit the "H".
Mike
Mike,
For clarity.
You are saying this
is the 9x57 Mauser(Haenel) using .356" bullets.
NOT
The 9.3x57 Mauser/Mannlicher using .366" bullets.
I leave tomorrow, but may try to slug the bore to get a bore measurement.
EDIT: At one time I had boxes of ammo for both of these calibers..... Sold them to a local guy a year or two ago.