We've been here before, but while I've heard periodically about "lug setback" in the 1909 Argentines, never heard such concerning other SA mausers or the multitude of German/Axis military rifles in WWI. With high probability of same generic era steels used, seems strange "if to intentionally" subject Argies to differing heat treating results! German rifles of the Great War, many reflecting heavy duty battle years & appearance, 'vet' status without the "soft" phenomenon speak or 'rep'. Contrast some quite nice 1909 rifles & carbines, apparently with such situation! No appearance of thousands of rounds fired! Within recent months, didn't Jon Speed make some comment in GB Mauser Forum about "un-heat treated" receivers from DWM furnished to Argentina per that govt order...? I have both DWM and local Argentine mfg Engineer carbines which do headspace properly! Due to ammo situation, never fired under my watch!
A conundrum seeking enigma... Or reverse!
Best & stay safe!
John
