Well, by the way you have worded your question, I would have to say the mouth calls are by far the most effective, mainly for the reason that both your hands are free to hold your gun!! As with any type of friction call, you must work this type of call with both hands, hence hindering yourself at times if the bird comes in too quickly. With the mouth call in place, you can call with your face right snug up against the stock of your gun, making this type of call the most deadliest of them all. <img src=icon_smile_big.gif border=0 align=middle>