Mirage

This is an advanced topic and one that only impacts SBR and SBHR in the 100m game.  I can't speak to the 500m High Power game as I have never shot that sport.  I suspect it applies there as well.  New shooters should not worry about mirage at this point but read and note the last paragraph.  It applied to us all. 

At the last match at Pioneer it was HOT and HUMID.  Walk out on the sand to set the animals and it was REALLY hot and humid.  I noted that two good shooters struggled with Rams.  Like 2 and 3 rams after hitting 9 chickens and 10 pigs.  My point, they know how to execute a quality shot but animals were not falling on the 100m line.  When I finally got to shoot I was having a fair day and after hitting 8 turkeys I was shooting well.  When I moved to Rams I was ready to shoot just as well.

Let's step back first before I get ahead of myself.

So what is mirage?.  Google it or go here.  In general terms, it is when the air and the surrounding environment are different temps and thus light rays are refracted. Or in layman's terms, are bent or altered from their true origination.  There are countless articles written on the topic so start here and click through to the read.  Or here.

(note:  there was a great article in USAShooting Sports before it went digital and it had a pencil in a water glass demonstrating how moisture refracts light.  I am trying to find that in digital form.)  Come back and see if I find it

Ok, so, now we're all well read on the issue.  What was going on at Pioneer?  I had the benefit of a good spotter and the use of some quality (Kowa) glass.  I took my first shot and it was a beautiful center break.  To my surprise I watched the bullet go right over the back.  I looked to my spotter who confirmed I was high.  I was so confident in calling my shot, what I saw and what my spotter saw that I took a full minute off my setting.  Took the second shot and It was another center punch break but the animal spun and it was hard for me to see the POI.  I told my spotter "center punch" but he reported rump.  Odd.  Third shot, I decided to hold front shoulder (left of center) and this time I saw the POI, still right of center.  Spotter confirmed.  Wow!  I held edge of sand/shoulder and NOW we get center POI.  I was lucky to a) have a good spotter, b) have a good hold and c) have great follow through so I could see the bullet so I knew something was up.

We both looked at the leaves after the first 5 shots and saw a gentle flutter left to right.  Not enough to move the bullet that much IMO.  I looked through the Kowa and saw mirrage moving softly left to right.  I decided to continue my left sand/casting edge POA and I ended up with 8.  First shot at 10 moa from chickens, changed to 9 moa and left hold.  I had one bad break and I missed.  Duh!

So, what in the world was going on.  I just can't imagine there was that much wind pushing the bullet to the right.  As I ran the mental tapes, I thought about mirage as the problem!


Some review and I think I may be on to something.  The first shot, high, certainly reinforced my belief that mirage was making the animal appear to be higher in elevation than it truly was.  And, the light left to right wind was also moving the image to the right making it appear more right than it was.  I need to do some more reading.  Another point made by Steve E., is that hot air is less dense than cold air and thus presents less drag on the bullet.  Another potential reason or contributor to shots going higher than what is normally expected.

So what is the take away?  The single most important take away is how important it is to develop your ability to call your shot and stay with the gun after the break to watch the bullet.  I know, when I was first told by veteran shooters you should see the hit and even watch the bullet go down range, I laughed...inside of course.  Well, they are right.  For rams, you should see the hit and often see the bullet go down range.  Sure, you need a decent scope.  Sure, it gets harder to see the impact on chickens and turkeys because they move so fast.  (I wonder if a 1/5th pig is heavier than a 1/5th turkey contributing to why they are so hard to see)  It just takes practice.  Practice on paper is key.  Note where the gun breaks and see where the hole appears.  Iron sights with spotting scope, air or smallbore, or any combo of the two.  This practice works!  Do that over and over and soon you will agree, you can call your break and see your shot develop on paper with a scope.  With iron sights, you make a mental note as to where the shot went and then look through a spotting scope.  Over time, you will be amazed at how good you get at knowing where the shot went. 

Now, if I would only do what I say and PRACTICE!

Note:  Here is a nice index to USAShooting Sports.  There are some good articles in here.  The issue I am looking for is not listed so I need to see if I still have it.  I may have given them all away.