303 Btitish question

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.

This has happened to me, I'm sure you just punched thru the center of your bredan brass. You got lucky, and didn't break your de-caping pin. I'm guessing the primer pocket is the wrong size for a new primer. Keep that berdan stuff around to "set up" your dies with.

When I saw three holes, I immediately reached to feel the bottom of the die to see how bad the decapping pin was damaged (Lee's so I was expecting at least a partial chip if not completely snapped off) but nothing....no damage at all. I check headstamps on my brass and anything that isn't commercial headstamp gets a visual check with a minimag light but I guess this one slipped by somehow.

Can you post a picture of the headstamp and holes?