Son and I machined up a scrap of seasoned osage orange into working fire piston today. It works!

But - with a 0.300" diameter bore and a 3" nominal stroke, it's a PITA to use and the coal is VERY small and short-lived. So... when we have another free evening, we'll make another, larger bore one.

It was a fun project to do together. I might also take a crack at a PVC pipe one as a Scout project - see http://www.trackertrail.com/survival/fire/firepiston/firepiston2Ron.html and watch the video at the bottom of the page.

Tom