88Mau - Some of the 12.7x44R are listed as rimfires. Some are listed as central-fire cases. Due to the period of make, they should all be centrefires. The picture shown by Lancaster shows a thin rim on the 12.7 cal case, consistant with centrefire cases. I think such a combination gun would be a blast and an impressive gun for shooting most of our big game! How I wish mine were just such a combination, however, with a proper sized ball (.703"), it will make a forminable bear/moose gun as it is. I am really temped to shorten the tubes, though and to install better sights. So far, I'm resisting myself. That stock will look pretty good when refinished - eh?