Here is one for the collective brain.

Today I am playing with a new round. It is a 300-221. I make dummy rounds when I am playing with new bullets and cartridges. This time I decided that the steel cased (wolf) would be the donor cases. I go through the process of making the dummy rounds. I get finished making my dummy rounds. I test my dummy rounds. The brass round fits in the chamber, the steel rounds don’t.

This is very illogical.
All should not work, or All should work.

Any clues?