I remixed this from https://www.thingiverse.com/thing:1567216, I wanted a way to fine tune the shell travel. In my case, my case pusher would not always travel far enough on the down stroke to always align 100% with the resizing die. The press would only do this a few times but it was enough to slow things down / break the rythm.

The plunger can be screwed in or out to fine tune the travel perfectly to your press, this should work for both 9mm and .40cal. The final version is a one piece as I didn't see the need to have two sections although I did have an intermediate version (pictured in the press) that I used, it worked fine, but a one piece seemed more streamlined.

The print did not come out perfect, this filament was quite finicky, I think I need to dry the filament, so while the print looks terrible it functions just fine.

I used an M3 screw, but since you need to tap the hole in both the plunger and pusher, you could use a standard screw of similar size. The threaded section is fixed into the plunger with a dab of superglue. There are also two holes on each side that could be used for set screws as additional insurance to keep things locked together once everything is set, this should be optional.