The information is wrong. The 5.2 x 68 mm cartridge was first used in Mondragon’s straight pull rifle of 1892 or 1893. The rifle used multiple locking lugs and had a marching fire device that fired the weapon as the bolt was closed. The stacking lug and bayonet attachment looked similar to the 1889 Schmidt Rubin. There is a picture of the rifle in a book in the Vancouver Public Library, but I can’t remember the title.