YOu can wrap a metal tang with rawhide, and it will shrink the wet leather down tight to the metal. With use, however, the leather takes on oils from your hand, and eventually stretches, and becomes a bit loose. You can re-wet the leather and and shrink it back down, or put new raw-hide on the tang, to cure this. This also happens with leather held to the tangs by rivets or screws. MY throwing knife lasted for 4-5 years before everything was coming loose. I was able to tighten the screws again, and that has taken care of the problem. But I don't expect it to last forever.
I made a knife years ago that has a leather handle made by cutting 1 inch squares out of thick belting leather, then cutting a hole in each disc for the tang, and running them down on the tang When I had the number of discs made and fitted to the tang I needed, I disassembled and put a good white glue on each side of each disc, and put them back down on the tang. Of course glue poured out of the sides as the discs were compressed, but that was my intent. I put on one more discs than the length of the tang required to cover, and then tighten an endcap down using a large wrench to turn it and squeeze the leather together on the tang.
I let the glues dry, and the next day I began shaping the handle using wood rasps. When I had take off the majority of the excess leather, I switched t coarse files, and then on down to smoother files. I made the handle fit my hand, rather than being geometrically similar. The term didn't exist then(1965), but today we would say the handle on that knife is biometrically designed.
This is not exactly what you were asking about, but I thought you should consider other ways to use leather to make a handle on a knife. Neatsfoot oil will preserve the leather.
no pics? 
