To kill a bird, you need to drive four or five pellets into a target roughly the size and shape of a walnut balanced on a pencil. The best way to do this? Throw a lot of lead. A 3-inch 12-gauge handles payloads of up to 2 ounces of small shot, more than enough to saturate a turkey's head and neck with pellets. Ten-gauges and 31/2-inch 12-gauges fling even heavier shot charges, but in my view, 11/2 to 13/4 ounces of shot suffice at ranges to 40 yards. Anything more is overkill at both ends of the gun. Ten-gauges are too heavy for the woods, and the extra payload of the long 12 doesn't kill birds any deader at 40 yards; it only generates more recoil.