Squid---I have the HS Strut Undertaker HS choke and is .675. I did like the preformance of the factory T/C choke supplied with the barrel with copper shot. But after killing a couple of birds at 40+yards with hevi-shot in my 11-87, I have become a big fan. Now that I am using exclusively my T/C Encore, that is the set up I settled on.