This happened to one of the shooters on shotgun competition. Firing pin on his Benelli Supernova stuck in forward position and slamfire discharge occured when he pushed forend forward loading shell into a chamber.

The problem was in firing pin. It is little deformed (probably from dry-fire trainings). That caused it to stuck in forward position. It looks like the metal is too soft and easy to deform:

Benelli Supernova Firing Pin Problem

Benelli Supernova Firing Pin Problem

Benelli Supernova Firing Pin Problem

Benelli Supernova Firing Pin Problem

I recommend to check the firing pin of your Benelli Nova or Supernova regularly and replace it if you see any deformations.

Firing pin is the same for both Benelli Nova and Benelli Supernova.

Recommended Product:
Benelli Supernova Firing Pin

Benelli Supernova Firing Pin

Get Benelli Supernova Firing Pin on Brownells