I would add one category of gun to my friend Jon's recommendations for high volume shooting. A British gun, 12 gauge, proved at 2 3/4" and 1 1/4 ounces, weighing more than seven pounds, a pigeon gun by definition, would be as suitable as an over under or an autoloader. Unfortunately, good pigeon guns are as rare in a reasonable price range as is a low mileage round action.