About 15 years back i took an Erma (cant remember Iver Johnson stamped on it anywhere though) .22 Lever action as a part trade on an old Shotgun.
Well it was a pain in the A$$ as no matter what brand of ammo i tried the lifter would not work unless i worked the lever very slow and most of the time i had to dig the fired case out with a knife.
I ended up selling it to a kitchen table gunsmith that wanted it with the problems.
Last time i saw him he was still shooting it as a single shot as parts were not available then.
I am pretty sure it was stamped made in Germany.
You got an Erma EG73 which was build from 1974 to 1997 (when Erma went chapter 11). They are much rarer than the .22lr versions. Got a couple of them and they work fine.
@chester: There seems to be something broken with yours. Normally their lever action mechanisms work perfect. Doesn't matter if operated very slowly or fast and if you stop somewhere in the middle. I have two dozens of these Erma guns in all variations and several bores and none had ever any issues like this. Even the version for the tiny 4mmM20 works perfect which is still a mystery to me. The later versions even handled mixed loads from .22short & .22long & .22lr without issues.