I'm sure this is not the right place for this, but I don't know a better place. I was watching a video today, I noticed a guy had a shotgun that was a combo pump and auto !? It had a charging handle on the side, a release button also, but it operated as a pump.

Any thoughts on what type of gun this is? I am very curious if this would work for 3 gun events. Any a and all input is appreciated.