The owner of the gun range where I last shot, stuck the barrel of big, and I mean BIG, stainless revolver into my my field of view as I was reloading my magazines. I turned to look at the thing, noting the length of the cylinder, and saying "what the heck is that", wherein he showed me a cartridge, I asked "45-70?!", he nodded, and proceeded to fire two or three rounds from a nearby lane, indoors no less!. Actually it didn't seem as nasty as a .44 Mag or even .357. Not much smoke either, so it must have been loaded with smokeless powder. One really big lead bullet though. But he did only fire those few rounds, and kinda shook his hand a bit afterwards. :)