MAC: "A 3 inch magnum shell loaded with 2 shells of #4 or #2 shot followed by 3 shells loaded with buckshot is more effective. And before anyone decries the use of #4 or #2 shot, get some and shoot them into a sheet of plywood at about 20 feet and look at the damage they do. No man can survive a chest hit at that distance with those shells and you could easily knock the legs out from under someone if you don't want a kill shot."

You are correct, sir. I worked many years as a paramedic in a small Georgia county. Our EMS was hospital based, our barracks were out in the ER parking lot. Many injuries are brought in by car, so, besides the hundreds of GSW I worked in the field, I worked many dozens more in the ER.
I was fascinated to see what kind of damage the different guns did to people. I loved to see the xrays of the GSW, a bullet really shows up on an xray.
Down South most people keep a loaded shotgun, in the closet or behind the door. Loaded with bird shot, maybe number 8 or number 6. Might have to shoot a rabbit in the garden, might have to shoot a bad guy. Or, might get drunk one night and get in to an argument with your daddy, and shoot him.

I saw 14 patients hit at close range torso shots with bird shot, I am talking a range of 10 to 15 feet, and every one of them died. A 1 1/2 inch "rat hole" entrance wound, no exit.
I never saw anyone hit with buck shot but, I would imagine, whatever bird shot would do, buck shot would do even better.

Close range shotgun hit is the most lethal load a person can be hit with.