Obstuctions in the Scope are Larger than They Appear

If you have spent a significant amount of time hunting, you have missed your fare share of shots.  This November, on opening weekend of rifle season, I suffered through a clean miss at 30 yards.  I got down from my stand and looked for any signs of blood.  After searching long enough to be certain that it was in fact a miss, I turned my attention to why.  My mind started running through the typical list of possible reasons... 

Was my rifle sighted properly? Yes, I shot it when I arrived at deer camp the afternoon before.

Did I flinch? Not likely.  I had a steady rest and I had calmed my breathing before pulling the trigger.

I couldn't figure it out.  I  climbed back in my stand and had a look around.  That's when I spotted it.  In my shooting lane about 15 feet from me was a single 1/2 inch diameter twig that was freshly broken and splintered.   The shooting lane was clear with the exception of this single small twig.  I thought that the odds of hitting that twig must be astronomical.  I certainly didn't even consider the possibility that I would hit it when I was aiming at the deer.  I don't even remember seeing it as I focused my eyes down range.  But the evidence showed that I had hit that measly twig and it sent my .30/06 bullet wayward. 

It wasn't the first time I had missed and it probably won't be my last but it sure would be nice to understand how it happened so I can minimize the chances of it happening again.  I'm a math teacher, so I sat down to analyze the miss from a mathematical perspective.  Here is what I came up with...

Our mind sees and opening for a shot but a projectile (bullet or arrow) needs a certain amount of clearance around any obstruction.  We don't see the clearance needed.

We see this.

But what we need to think, is this.

Conceptually that is what is going on.   I went ahead and analyzed it further.  I wanted to answer the question, "By neglecting to consider the buffer, to what degree are we lying to ourselves?"   Consider this simple example of a one inch wide twig, passing through a three foot square shooting lane.



1" branch with no buffer

1" branch with .30" buffer in red

This branch takes up just shy of 5% of the window for the shot, setting our expectation for success at 95%.  But what about the clearance for a .30 caliber bullet?  If we add that buffer in and count it as area that the bullet must avoid, our expectation for success drops below 92%.  Sure, that doesn't sound too bad but consider this. 

The branch excludes 60% more space than your brain told you initially.   



1" branch with 1.5" inch buffer in red



Bullets are small.  What about arrows?  I conservatively estimated that an arrow flight would need 1.5 inches of clearance for broad heads, fletching and wobble.   That changes the game significantly. 1.5 inches around the same twig blocks over 20% of the lane.  Going from 5% obstructed (what you see) to 20% obstructed (what you need to account for) is a 300% increase. 

The Takeaway

Anytime you intend to thread the needle from the deer stand you need to adjust your thinking about how  narrow an opening  you have.  It doesn't take much to deflect a bullet or arrow.  A branch or twig that you thought was inconsequential could sent your shot off target causing a miss, a wounded animal or a carom to who knows where.   And it is more likely to happen than what your brain normally tells you.

What can we do about it?

As hunters, we want to be as concealed as possible with cover between us and our quarry to shield our movements.  One key part of the solution is back cover.  Cover behind you serves to breakup your outline and can be very effective concealment.  Another key is well cleared shooting lanes.  When setting up your stand before the season, consider what your lanes will be like in throughout the fall.  During early archery season the leaves will still be on the trees but expect many of the leaves to be shed by the rut.  You can avoid obstructions altogether by setting your stand on a telephone pole. Or you can bury yourself in a briar patch too thick to draw a bow much less thread a shot through.  There is definitely a balance to be struck.  To help find that balance, try visualizing the buffer around the branches that might obstruct your shot.   After you give yourself that buffer and if you are uncomfortable with what you have, trim a little more. 

-KF