Found one more interesting pic from recent training. This what can happen to a shotshell:

Unusual Malfunction on Pump Action Shotgun (Benelli Supernova)

Unusual Malfunction on Pump Action Shotgun (Benelli Supernova)

Unusual Malfunction on Pump Action Shotgun (Benelli Supernova)

Unusual Malfunction on Pump Action Shotgun (Benelli Supernova)