Well Altamaha, I have never handled a Mexican small ring action, but from your photos I guess the Mexican action is not only small ring. From the position of the extractor collars it seems to be an "intermediate" action too, the bolt about 5mm = .2" shorter than the standart large ring M98. The Kar98a actions used by the German gunsmithes post-WW1 are of the same length as the large ring Gew98 actions, so the magazine length limitations do not apply. So I would use these for any cartridge in the diameter and pressure range as the original 8x57S cartridge, that is the hot European CIP pressure loads, but not for any "Magnum" pressure cartridge, be it belted or rimless. So for me the 9.3x62 would be "in", the 9.3x64, 8x68S, 6.5x68 and all American Magnum cartridges "out".