Great info about the powder and the extra spring! Thanks!
I did fire my AG42B with 20x of Federal Blue Box 140g ammo a while back... ‘‘twas interesting to say the least.
Had to mortar the gun a couple times to extract stuck cases (suprised I never ripped off the extractor). If I remember correctly, the fired primers slightly backed out of cases too.
Have not tried any of my factory PPU, but I will give that a try as well as my handloads.
I have had “fun” with all of my pre 1950 designed Semi Autos. They all have their inherent issues it seems. (SAFN49, AG42B, G43, SVT40, Hakim, even the venerable M1 Garand).
My SAFN49 was the one I learned about OOB firing and bent/stuck firing pins and slamfires. Good times! 2 piece firing pin is a must.
BTW, for the AG42B, 4064 would be a good choice since it would lower port pressure.




















































