I wasn't that into noir when I was a child.

I think there was even one more evolution where the plastic caps came in a strip instead of a ring. The strip was put in a magazine that slid into the bottom of the pistol. Most of them just moved the strip up as they fired, but if I recall correctly there were even ones that cut each cap off individually after firing it and ejected it like an empty shell. Awful for litter, but pretty cool for cap gun technology. I am pretty sure all of this stuff has been banned where I live.

Usually what would happen is the residue builds up on the parts that feed the tape up so it would stick, and lose index. The hammer would land between caps because the tape wasn't advanced the distance it needed to be.

If you clean all that off so the tape consistently advanced the correct amount you wouldn't have issues.