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The Sharpness Factor

Text & Photography By Russell Thornberry

photoMany bowhunters don’t understand how the “sharpness factor” figures into bowhunting success. First, one must realize that game animals shot with arrows die from blood loss or hemorrhaging. Arrows, unlike bullets, have relatively little foot pounds of impact on big game animals.

My 80-pound compound bow delivers a 660-grain hunting arrow, leaving the string at 245 fps, with about 88 foot pounds of energy. Compare that with a .270 Winchester, 130-grain bullet leaving the muzzle at 3,100 fps and developing well over 2,500 foot pounds of energy. When you compare 88 foot pounds to 2,500-plus foot pounds, it’s easy to see why the impact of a hunting arrow means virtually nothing in terms of lethal impact on big game. A firearm relies on tissue damage and hydrostatic shock created by bullet impact to dispatch an animal. There just isn’t enough “oomph” in an arrow to do that.

In bowhunting, it’s all about the broadhead. It must slice cleanly with little or no bruising or tearing of the tissue. In very simplified terms, when a razor-sharp blade slices living tissue (muscle and/or organs) without bruising or tearing the tissue it has sliced, the brain fails to initiate the process which causes blood coagulation, resulting in extreme hemorrhaging.

The faster the hemorrhaging, the faster the oxygen supply (which is carried in the blood) is deprived from the brain, rendering the animal unconscious. Most animals taken with bow and arrow fall to the ground unconscious before death actually occurs. So, for bowhunters, the object is to create massive hemorrhaging with a razor-sharp broadhead. The sharper the broadhead, the quicker the animal will be dispatched.

Photo: The Stirling Sharpener, the author’s favorite device for establishing the angle of the blade (21 degrees per side, 42 degrees overall), is the first tool used in his three-step sharpening process.

Now, back to that original question: How sharp is sharp enough? Simply put — razor-shaving sharp! Anything less is irresponsible and unethical. A broadhead should shave hair cleanly and effortlessly. If your broadheads won’t do that, then sharpen them or throw them away.

This brings us to the crux of the matter: Most hunters don’t know how to put that true razor’s edge on a broadhead, or even a knife blade for that matter. They buy pre-sharpened broadheads and assume they are sharp enough. Regardless of what it says on the package, if the blade won’t melt hair cleanly off your arm, it isn’t sharp enough for hunting purposes.

Ragged Edge vs. Smooth Edge
There is an ongoing argument among bowhunters about the best way to sharpen a broadhead. Some argue that a ragged edge kills quicker or better than a smooth razor’s edge. This argument can only exist where there is ignorance of what causes the greatest degree of hemorrhaging in the first place. The ragged edge proponents are simply wrong. A ragged edge creates minute tearing of tissue as it cuts, something like the teeth of a saw. That tearing actually helps initiate coagulation. A smooth razor’s edge does not.

If you have ever nicked yourself while shaving with a safety razor, you can attest to the difficulty of stopping the bleeding. This free flow of blood occurs because coagulation is not initiated, due to the fact that the tissue was not bruised or torn.

Compound that same principle by the lethal blades of a broadhead passing through internal organs and you begin to understand the massive hemorrhaging created by such a wound. The bottom line is this: The sharper your broadhead, the faster it dispatches the game through which it passes.

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