The Cutting Edge: Broadhead Sharpness Matters

A few things you should keep in mind when preparing for your next hunt.

  1. The broadhead does the killing.
  2. The broadhead kills the animal by exsanguination (bleeding sufficient to cause death) or by collapsing the lungs.
  3. A laceration caused by a sharp object always bleeds more than one made by a dull object.

Let’s examine those points in a little detail.

If you think about it, the only thing you purchase for archery that actually kills the animal is the broadhead. Regardless of the bow, the arrow, the sight, the release or any other accessories you own the broadhead does the actual work.  This point is very important to keep in mind when purchasing your gear.  You want a broadhead that is tough, sharp, cuts a large area and stays sharp as it cuts.  The design and metallurgy of broadheads is way over my head but I know there are a lot of broadheads on the market that meet the above requirements.  So, I will not get into which broadhead to use, rather this article is regarding only the blades of that broadhead.  A whole article dedicated to the importance of broadhead sharpness may seem overkill, however that should demonstrate how critical that sharpness is.

When an animal is shot with bow and arrow, it is blood loss that will cause the shock and eventual death of the animal. To a smaller extent, pneumothorax (air leaking from lungs) and hemothorax (blood leaking from lungs) can also cause the death of the animal.  An arrow is considered a low velocity projectile with kinetic energy less than 100 ft/lbs.  Even a 9mm handgun produces over double that amount of energy.  The kinetic energy of the arrow striking the animal is not sufficient to cause the immediate incapacitation of the animal like a rifle can.  Instead, we must rely on the broadhead cutting blood vessels or lung tissue as it transects the chest cavity. (Lacerating the heart will also cause death, but for this article, the heart will be considered a blood vessel.)

It is a fact the sharper the instrument that lacerates these tissues the faster the blood or air loss and the longer it will take to stop the bleeding or air loss.   Blood vessels are very elastic and are only actually secured within the body by connective tissue in a few areas.  Therefore they can move around when something pushes against them.  If a dull blade strikes a vessel (artery or vein) it will push the vessel out of it way.  Sometimes it won’t even lacerate the vessel.  But, if it does lacerate the vessel, it won’t cut as much of the vessel and the cut can be jagged or a partial tear. A jagged or torn vessel will create turbulence as the blood leaves the vessel and will slow the blood loss.  Also, blood clotting is influenced by the amount of surface area platelets have to bind to. Jagged or torn vessels have more surface area and will provide for quicker clotting.

Moral of this story is that the bleeding will stop sooner and less total blood will be lost when a vessel is cut with a dull instrument as opposed to a sharp instrument.

Lung tissue is very spongy and pliable with an amazing ability to seal itself when cut or penetrated with a less than razor sharp object.  If a cutting instrument is dull when it strikes the lung tissue, it will stretch it until it tears.  After the lung tissue tears, it will retract like a cut rubber band pulling back into itself.  The retraction of the damaged tissue will cause swelling at the injury and the amount of air lost through the injury will be greatly reduced.   These types of injuries can seal themselves and allow for the animal to live for a long time.

I was hunting with my uncle, many years ago, when he bagged a buck that had been previously shot with an arrow through both lungs. The injury had healed almost completely and the buck appeared healthy when he shot him.  We only found the injury during field dressing. The arrow was still inside the buck and through both lungs.  There was major scarring around the arrow but the rest of the lungs appeared functioning and healthy.  I don’t believe the injury would have been survivable with a razor sharp broadhead, but I don’t know what was originally attached to the arrow because it had been broken off.  However, in my experience a razor sharp broadhead through the lungs is not survivable and should result in a very short tracking job.

One additional element that should be mentioned is regarding the adrenalin surge an animal can have when injured.  If you have ever cut yourself with a very sharp instrument and a dull instrument, you probably noticed the cut from the sharper instrument resulted in a lot less pain initially.  I don’t quite know all the science behind such a phenomenon but I know it is true.   I have also noted the reactions of the big game animals I have arrowed.  With a razor sharp broadhead tipping my arrow I have shot animals that appeared to not even notice.   I arrowed one cow elk with a complete pass through lung shot where I saw the hit perfectly.  The arrow zipped through the cow quickly and stuck in a hill behind her.  She jumped and then just began walking off.  I began to doubt the shot when I saw the blood on her side and she stumbled.   She then sprinted about 15 yards and collapsed.  I don’t believe she knew she had sustained an injury until she went into shock and couldn’t breathe. This did not allow for her to have an adrenalin surge.

As a counter to that cow elk, I have been with hunters who arrowed animals that ran for a couple hundred yards after being hit with nearly identical shot placement.  When I checked my hunting partners’ broadheads, I noted they were much less sharp than what I would recommend for hunting.  This has happened twice that I can remember off the top of my head and both times it appeared the broadheads had become dulled from riding in the foam of the quiver for a couple years without being sharpened.

I investigated why the bucks had gone so far due to a fascination with the how and why animals don’t always lay down and die as easily or quickly as they should.  I believe it has everything to do with their adrenalin.   Wild animals are very tough when push comes to shove, but I believe they will expire much more quickly when their adrenalin not surging.  A dull broadhead causing pain could be all it takes to make the animal’s adrenalin surge and I would rather that did not happen.

When bow hunting I desire as short a tracking job as possible and a quick clean kill.  A razor sharp broadhead gives me a strong advantage over a dull broadhead and helps provide for that quick clean kill.  A broadhead’s sharpness is one thing we, as bow hunters, can test and control. It’s hugely important to the killing power of our weapon of choice and can save us from many hours of stress caused by tracking a wounded animal.

 

Happy Hunting, Kevin