That 2,67 gramm = 41 gr rifle flake powder / steel jacket bullet” service load would be on spot for a 8x57I with the original 14.7 g = 227 gr bullet. I don’t know about any German “11 mm” cartridge with such a low service load. Even the smallest, the 10.75x57, was loaded with 3.5 g = 54 gr of the same powder. Maybe the barrel was replaced or rebored by Peterlongo in Austria? If so, there should be Austrian proofmarks below the wood.