I suspect just about any turkey choke will kill the snot out of them with a full 2 oz load of #9 TSS out to 40 yds. If you want to reliably go out to 50, I'd start with a .660 or .665 and definetly pattern it to be sure. Indian Creek seems to be the favorite flavor nowadays. (Disclaimer- I do not hunt with a 12g... so I have no real world experience; just info I've gleaned from reading)