No concussion, but you would think it would knock enough sense in me to go 3 inch. It hasn't worked yet. As for the ported choke tubes, they do take some of the kick out. I'm just going to stick with what has worked for me, Rem. hevi shot mag. 3.5" and Rem. Wingmaster 3.5". I have enough of them to last me the next two or three seasons, so there is no need in changing now. I'm still thinking about trying the Indian Creek choke though. Curiosity is killing me.