I've had a Mk. VI for a few years. It took me about a year to find one, but I wouldn't call that rare. Factory ammo is a bit hard to find, and rather expensive. I found some old stuff with a Garate Eibar revolver from an estate sale but still haven't shot it because I realised it's collectible in itself. Fiocchi makes a batch every now and then. I load my own. There are a couple of sources of new brass converted from other calibres (e.g. .45 Colt) which I got from Buffalo Arms in the U.S. a few years ago. I got cast bullets from a shop in Ontario, the name of which I can't recall right now, and they do brass, too. We've covered this topic before, so if you do a search on this site you should find all the details on sources.