We mustn't kid ourselves, though. 16's don't magically kill any rooster that presents itself. There's science to it, especially if we're talking about the Game Loads mentioned by JMc above. I think I'm right that those are s...l...o...w loads. At something less than 1200 fps, especially w/ small shot (6's or smaller), they simply won't have the energy to penetrate a rooster or break critical bones much past 30 yds. Might get a golden BB in the head or boiler room, but that's pushing it. Thus, my preference for #5's & velocity around 1300. Factor in a modified choke, & you get an honest extra 10 yards of effective range. That's the science. The art is putting it in the right place at the right time. IMHO