I’ve never fired a blank round bigger than .22cal. I’ve noticed that even the minor recoil of a .22 is diminished when the round is a blank. Does anyone know if there is markedly less recoil with a .30 cal blank round?
Recoil with a blank 12-guage shotgun round is minimal—maybe about 5% of the recoil of a loaded round (obviously).
Thus, I think there would be no doubt to an experienced shooter as to whether the round was a blank or loaded.