I made myself a fox whistle out of two used shotgun shells. 5 minutes of fiddling about and i have a shiny new toy. It sounds like the real McCoy... I can get some real volume out of it too, more so than the button whistle I have. They say the proof of the pudding is in the eating, so I'm hoping to try it out in a few weeks on a new property. The Youtube tute shows how simple it was. https://www.youtube.com/watch?v=tnpcCx6r8fo