No real magic in blowback pistols for high power cartridges. most Chinese made pistols from before the end of WWII were in 7.65mm B or 7.63mm Mauser were blowback. They made copies of both the FN Brlowning M1900, the Little Tom and the Mauser M1910 chambered for 7.63mmM, in addition to many local designs. In general, these pistols in 7.63mmM were larger than the originals with a heavier slide. I have seen some quite small Chinese pistols in 7.63mmM and they inevitably have a lot of metal in the slide, up to almost a half inch thick on the sides of the slide. Sufficient weight in the slide and a proper barrel length and a blowback will handle the 9mm Luger and the 7.63mm Mauser cartridges. I have seen some of these that are selective fire and quite well used with well banged slide stops, but otherwise sound. Most pistol ammo in China in the 1920s-1940s was imported I am told.