Wandered into an Auction, checked out the selection, stayed and purchased a 98% M 51. One thing for sure, the experts need to get hold of these before they write. I did in fact find that the M51 has a slide hold open, not the last round fired type, device, but one that is great for cleaning or reloading a new mag. Handy and easy to use. Also it has a cocked indicator, I may have missed that on some of the reviews but it also is sight and feel setup. Neat lighweight and recoil easy. Made about 1918.