[geoschmo]

Probably 8. That's the most universally accepted I could find, although I did find a couple places claiming more.

According to http://www.gebirgsjaeger.4mg.com/Gebirgs3.htm#Weapons it was 8 rounds

Another source claiming 8
http://world.guns.ru/handguns/hg67-e.htm

another source claiming 8
http://www.thesouthafricanwargamer.co.za/weapons.htm

According to http://www.arniesairsoft.co.uk/revie...ger_review.htm :

12 rounds with a standard magazine
50 rounds with a drum magazine