If your shoulder gives you serious trouble.......you may wanna go .410 for turkey.
I have a healthy shoulder. And I've never been very recoil-sensitive. But a 3" turkey load in a single 20 is NOT your average pussycat. Especially if you have to twist out of position at all. My gun has a pretty good pad on it. But it's still fairly snappy on the hind end. Never did the actual math for free recoil. But I'd say it's close to the same as a 9 pound .300 Magnum.
