Los pistolas son solo para experimentacion, yo creo.
Josef Nickl did, I think, design the famous Mauser Models of 1910 and 1914. The book suggested above, "System Mauser" does have more on the subject. I'll check another Mauser book later and let you know what I find. My guess is that those were blowback -operated and not strong enough to handle the 9mm Parabellum load. Never made it into production. I know the barrels rotated, but maybe still not strong enough. The Steyr-Hahn rotating barrrel lock must have been stronger?
And the Mexican Obregon?
De donde son ud.? Bienvenidos a la forum. My Spanish is poor, but others here speak/read it better. We have members in Argentina, Uruguay, and Mexico. (And Brazil, but they speak Portuguese.)