Let’s suppose that you find yourself in a situation where you have a knife, but you need a saw. Or, you have a large hunting knife, but you need a small skinner. One approach is to bring all those items with you, which few of us remember to do. Another approach is to bring the massive answer — something like a multi-tool or Swiss Army knife. One of those probably does have the tools, but in a size too small plus everything else you don’t need that day.
With a blade changer knife you can trim down your tool kit, with one handle and several interchangeable blades. Convert the hunting knife to a skinner, the pocket knife to a saw, and although you have fewer options you do have the tools you really need.
In real life this kind of universally useful knife is difficult to build in a style that disassembles easily and rebuilds securely. Unless there’s a compact storage system that holds all the parts, extra blades are apt to be quickly lost. Even careful backwoodsmen know how quickly small items can permanently disappear in the back country. Set that important item on a log, turn your back, and it’s gone. You’d swear the windago was real.
On the other hand, it’s a great idea and saves on space and weight. And of course, none of us are so careless as to actually lose a spare blade.
The Case Changer Hunting Knife includes two styles of knife blade and a saw, with a compartmented belt pouch.
Case’s XX Rosewood Changer adds a gut hook blade to the assortment, plus classic rosewood and brass fittings.
The Kershaw Blade Trader is a full sized field dressing kit for big game. Three blades and the handle fit in one neat holster.