I'm resizing some mixed headstamp 1x fired 303 British that is mostly commercial with a few mil in the bunch. I'm setting aside any that are harder to deprime than the rest because of the primer crimp when I notice 1 I just ran through appears to be BERDAN primed but where the anvil should be in the center between the 2 flash holes, there is a larger flash hole just like in Boxer primed. 3 holes and no anvil and I yhought "What the Heck?!?!?".

This hasn't been previously resized and the anvil drilled out (it still has the primer crimp) so I'm wondering if anyone has any ideas? I've never seen any brass that has 3 holes like this and I guess it could be possible that my resizing die hit just right that it punched the anvil out but the hole is dead on perfect.

Headstamp is "K 1939" at 12:00 and " C II" at 6:00.