Re ERMA ammo sensitivity
see attached post start on page 3
https://www.mdshooters.com/showthrea...=218955&page=3
These shooters in Maryland analysed the jamming and It would appear that the chamber was not deep enough for most 22LR and the projectile was in the lands before fully chambering - just enough to jam the reload.
Reaming the chamber a fraction deeper seemed to solve the jamming
a good read for ERMA owners