Graves gun revolver acting like a semi ?

Soooo.... Graves weapon is a shogun with a revolver magazine right?

Then why are the casings ejected of a revolver? that's not how a revolver works. Unless is a semiautomatic shotgun., witch is not as you can see in one of graves animations he opens the shotgun as a break barrel style gun. Just pointing out little details that may seem trivial, but actually takes away from the character weapon when people that know firearms play him like myself. Wondering if they can change or make new animations for it