Steyr is an Austrian manufacturer (named after the city where the company is located). As Oldtimr mentioned though, the rifle could have been used anywhere. If the markings do represent animals that have been taken (and the rifle was used by an Austrian or German), the H would stand for Hirsch = Red Stag. The G would represent Gams = Chamoise. RB I assume is Rehbok = roe deer buck. S might be Steinbock = Ibex. I am not sure what the other initials could be. I am going to think about it a little more and try and figure it out. just thought this might help.