Pivi - I just noted that I did not answer one of your original questions in opening this thread. There are many cartridge case types that are similar to the 8 mm Ultra, such as the 7.63 Mannlicher, the 7.63 Mannlicher Experimental, the 7.65 mm Bergmann No. 8, the 7.65 mm French Long, the 8 mm Bergmann No. 4 and the 8 mm Roth (even the 8 mm roth Steyr, although short in the case, is somewhat similar). Regardless, the 8 mm Ultra is its own case type, not interchangeable with any of the others. I stressed case type, because the bullet of the 8 mm Ultra is quite different than the others, with its flat nose. It is actually more reminiscent of the 8 mm French Lebel Revolver projectile than that of any of its pre-WWII auto pistol “cousins.” The projectile is a major identification point, although hardly needed unless found out of a cartridge, since all known 8 mm Ultra cartridges are properly headstamped with the caliber.
GWB - I fully understand “old and lazy,” but am disappointed to know that I am not the only specimen of that condition. I thought I was unique. Yes, the headstamp on the aforementioned 7.63 Mannlicher round is quite nice, and somewhat scarce. There are variations within that general headstamp. Actually, aside from the 1947 Argentine headstamp and perhaps the S.F.M-headstamped rounds, none of the 7.63 Mannlicher rounds could really be called common. They range from scarce to pretty rare, and are a fun little group of rounds to collect. I have a little over 40 different 7.63 Mannlichers in my own collection, and am always excited to find one I don’t have. I certainly enjoy having the single-specimen rarities like the 8 mm Ultra, but once you have it, and have oohhed and awwed over it for a few days, that is pretty much it. With groups like the 7.63 Mannlicher, it is conceivably possible to get them all, although few achieve this including me, but that leaves the interest and opportunity in adding to the collection open. Once the rare single-specimen rounds are acquired, that door is shut. I guess that is why calibers like the 9 mm Para are so popular with collectors - you can add one a day for every day in your lifetime, and probably not have nearly all of them. Areas of collections that can grow are more interesting to me than ones that have no where to go.