I didn't realize it until I saw the pictures that I am pretty sure I had fired one of those at a range back in the 90's. When I first started shooting AR's, I swore I remembered the one that I had shot all those years before kicked alot harder and the racking mechanism was on the side or the top. I still can't remember if it was a semi or full.
It was old as hell though too. It jammed constantly, either FTF or stovepipe. That I remember clearly. I thought it was a piece of shit, I swapped it out for a Thompson, which I ended up having alot of fun with.