I think Seven plus One has the best explaination on blanks using black powder.
On another thread another poster said the piece on the top barrel looked like a “blank adapter”.
We all know that either this was a pure photoshop fab or they posed him with a blank firing shotgun and set the camera to capture the smoke “evidence”. This asshole still has no clothes!!!!
There is no earthly reason to need or use a BFA (blank firing adapter) on a break action shotgun. BFAs are only needed to increase pressure enough to make semi and full auto actions cycle.