Grouse Guy,
Is the rifle's model number shown on the receiver ring? If not, which feature of the rifle causes you to believe it might be a mod.1925? It would be helpful if you posted a photo of the rifle and post photos of the original Austrian proof marks( if any)on the barrel, hidden by the stock. The 7.62mm is the bore( not groove or bullet)diameter in the British system, and is not necessarily the nominal cartridge designation. Under the Austrian system, the barrels were usually marked as to groove diameter. "Slugging" the barrel and making a chamber cast is the most positive way to ID the chambering. If the rifle is a rebarreled military rifle, it could be chambered for different cartridges that were not available as factory chamberings; a chamber cast would sort this out.
Mike
