I have a 12 GA. pardner, 3 1/2 chamber, full choke. Its the National Turkey Federation model. I shoot 3" slugs and 3 1/2" turkey loads, both of which are "stiff", but manageable. Everything that I have killed with it have been one shot kills, drop right in their tracks. Works well on Canadian geese too. Don't let the turkeys get too close.
I did switch to a Handi 45-70 for deer and bear, using Hornady LE, and the recoil is somewhat less. I switched just to be able to take deer at 100 to 150 yards, which I couldn't with the slugs.
The Hermit