The two shells in the center of this photo are paper dummy 3" .410 shells.
The headstamp reads; Winchester Made In USA
The word Dummy is on 2 sides of the shell and it has a rolled crimp.
I was told these were made for the Winchester employees to cycle the guns during assembly but also that they came with Model 42 pumps. The Model 42 came in 2 1/2" and I have never seen the shorter shells in dummy configuration.
I’m curious how common these are and what others know about them.