ANSI-SAAMI .38 Special

These weren't modeled with printing in mind.
Just as a useful point of reference when modeling other things.
This .38 Special cartridge is modeled to ANSI-SAAMI dimensions (https://saami.org/technical-information/cartridge-chamber-drawings/), with the exception of the undercut in front of the rim, and the primer pocket and primer (https://ballistictools.com/articles/primer-pocket-depth-and-diameter.php).
From the top of the case's base, the undercut is 1mm tall and 1mm deep.