Resurrecting this old thread, just to add to the list of cartridge designs ripped off by the victors of ww1
The 6.7x63 was absolutely interchangeable with the 270 win. My late friend in Austria informed me that apart from differences in sighting, there is no difference at all, extraction of a fired case shows no changes. His family got rid of his and his fathers rifles and guns as if they were a plague, and I had no chance to make any offers after his passing, nor could I glean more info from the web. A search did turn up a drawing of a 6.5x63 that looks rather like the wildcat 6.5 06, but the 6.7x 63 remains elusive . It was designed by Neuber and Sohn circa 1911, also Austrian