The crown G means it was proofed for a single projectile. The 118/35 is the bore( not groove or bullet) diameter, expressed in gauge measurement. This works out to about 8.64mm or about .341". Experience shows that barrels with this marking commonly "slug" to .357-359" groove diameter. The most common chambering with this mark seems to be one of the 9.3x72R cartridges, but sometimes it may be found on one of the other case length 9.3 cartridges( 70-82mm) or some 9mm cartridges such as 9x58 1/2R S&S. The best way to determine the chambering is by making a chamber cast. If it were mine, I would try a 9.3x72R normal. before making a chamber cast, however.
Mike
