38 Super - Idle speculation....

[56hawk]

Luger never really accepted that case mouth support would give enough obturation and had the Luger chamber made with a "step" about 5mm back from the support shoulder; that oddity was retained until well into the WWII era in the P.08 (it never was used in the P.38 or German SMGs).

I always wondered what the heck that was. It really looks like it has a two piece chamber.

 

[Jim Watson]

Hmm. I have seen in person and pictured on the www 9mm empties with a distinct band around the case mouth. Guess they were fired in a real Luger.