Yesterday I was looking thru some ammo I had bought at an estate sale. There was a 20 round paper ammo box that had about 4 or 5 458 Win Mag cartridges in it. When I looked in the bottom there were several pistol size rounds in the bottom of the box. When I dumped them, they were loaded, lead bullet rounds. The headstamp was "R-P 38 80". Never heard of that before. I Yahooed it and couldn't find anything. I have the 60's Cartridges of the World, but not here.