If it's a normal Drilling, (1 rifle and 2 shotgun barrels), and it has a scope, then it doesn't matter too much what it's regulated for. Just chose a load and adjust the scope. Or adjust the front sight height if it only has open sights. Colt developed an association with JP Sauer & Sohn at the end of the 1960's and I don't think Sauer Drillings of this period are stamped with a working load. My 1956 S&S 7x57R Drilling has no such mark.
Regarding paper-punch holes; RWS use a style of bullet developed by Wilhelm Brenneke that have a "sharp-rim", that cuts paper-punch like holes in paper and which are intended to do the same thing in animal hides. I saw these factory targets being shot at an indoor rifle testing range in Steyr - no shortcuts there !
