Dealing with mirage…

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Went to the range the other day to shoot at distance. After zeroing I shot a cold bore shot at 585 yards and nailed about a 6in steel twice in a row. Messed around a bit in different shooting positions, felt pretty good about stuff, then as the afternoon progressed I backed up to 700-1000 yards.

I started noticing I was missing about .3-.4 mils high, fairly consistently. First shot might be close or on, but then I would be high.

I had my labradar with me so I was tracking and accounting for increased velocity as my powder temp increased. Furthermore I was using my Fury 5000AB binos which was accounting for changing environmental data. Even with that accounted for (increased DA, increased MV.) I was still missing high. I even debated that I had somehow lost my zero.

What I deducted was occurring after the fact that I was dealing with mirage, both barrel and environmental. I was using a suppressor but even with a cover there was still a significant amount of mirage after more than a handful of shots. Also with a cool night before and a bright sunny day there was a fairly high environmental mirage as the afternoon progressed, with relatively light wind (a boil.)

Doing some research, this explains why my shots were high in the afternoon, and this got more pronounced as my barrel heated. I’ve long known that mirage can be used to aid in wind calls, but never really understood or appreciated how much it can displace your target image, causing you to miss.

There are quite a few YouTube videos and articles out there on this but it was never something I had really learned about prior, despite being around long range shooting for a minute. I always figured it was either me or my rifle previously, or there was enough wind the mirage effect was more lateral and could be dismissed as wind effect on the bullet. It also explains why I always seemed to shoot best late in the evening when mirage (and wind) was less.

Anyway, though it was a somewhat frustrating range day, I learned something so I figured I’d share. Might be something that needs to be accounted for in a hunting situation as well!
 

Flyjunky

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I've also read that changes in lighting have an effect on apparent poa, just like mirage....just something I've read about.
 

Formidilosus

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I've also read that changes in lighting have an effect on apparent poa, just like mirage....just something I've read about.


In iron sights POI tends to change with differing lighting, but that due to not being scale to see as well as pushing the front sight higher on the bull. If mirage is removed, I’ve never been able to change the POA due to lighting using a scope in a vice and checking through the day with clouds and even at night with artificial light.
 

Ernie

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Went to the range the other day to shoot at distance. After zeroing I shot a cold bore shot at 585 yards and nailed about a 6in steel twice in a row. Messed around a bit in different shooting positions, felt pretty good about stuff, then as the afternoon progressed I backed up to 700-1000 yards.

I started noticing I was missing about .3-.4 mils high, fairly consistently. First shot might be close or on, but then I would be high.

Anyway, though it was a somewhat frustrating range day, I learned something so I figured I’d share. Might be something that needs to be accounted for in a hunting situation as well!
A number of years ago, I shot my first 1K F-Class match when we/USA was hosting the World's at the Whittington Center, just outside of Raton, NM. My first relay (Nationals took place before the Worlds), my drops was fairly spot on. I was shooting Open with a 284 Winchester and 180 Hybrids. By the time I had my third relay it had heated up quite a bit, and I had to bring my drops down. The following morning, I went back to my original drops, and put my first shot in the X-Ring. In the afternoon, I went back to the drops I had used the afternoon before, and I was close, unlike my first afternoon shooting.
There can be vertical (not just horizontal) with wind as well, and even more so when combined with terrain.
Terrain and or shooting across a canyon or ridge can be really tricky, when stretching things out.
Best advice I can give, is to practice in ugly conditions from multiple field positions (with varying terrain if possible). It will be humbling, educational, and fun. Reading mirage is a perishable skill, so IF you are not shooting, spot for others.
We tend to have more animal movement when conditions are typically better.
Antelope would be one of several animals that you can hunt all day long-so there is that😇
If you are unsure....Get Closer.
 
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Ernie

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Of course it could. But I prefer to hold wind, and use my reticle to do so.
Roger that.
Depending on much you turn your magnification down, the magnification range of your scope, and the actual reticle you are using, it may take more time to see your wind holds well.
There are a number of ways to skin that cat, and yours works well
 

Lawnboi

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Roger that.
Depending on much you turn your magnification down, the magnification range of your scope, and the actual reticle you are using, it may take more time to see your wind holds well.
There are a number of ways to skin that cat, and yours works well
Can be. But generally for the reticles I use, at distances I’m holding wind at, I can get away with a pretty small reticle.

When I’m shooting under pressure I want ffp. Part of the reason I choose that is mirage.

Mirage, like wind is a variable that’s difficult to nail down and always seems to be more of a guess. Recognizing it as a situation that can cause an unknown should be accounted for.
 

Lawnboi

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Understood
Really agree on reading mirage to be a skill. When I started shooting longer range, I saw all the squiggly line diagrams, and figured that was easy.

In practice mirage takes time to recognize what it’s really doing. And even then can sometimes be a variable that I won’t even pay attention to. Noticing subtle changes, while shooting under pressure, is what is needed, and takes getting out in alot of conditions to learn.

Similar to your story, my first match I trued my rifle on a range that had significant mirage. I trued because that’s what everyone said to do. The next day on a broken terrain, natural foliage range, my elevation was off significantly. Being a new shooter it took me far too long to recognize that. It is now something I really pay attention to anytime I’m zeroing or confirming elevation.

At least that’s my novice 2 cents on it
 

Jimbee

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Does mirage generally cause your impacts to be lower? I shot some today and shot a couple rifles at 100 yards just to confirm zero after struggling at distance (windy). I was shooting over bare dirt, prone, sunny. Mirage was significant. Both groups were .4ish mils low at 100 yards.
 

Ernie

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Does mirage generally cause your impacts to be lower? I shot some today and shot a couple rifles at 100 yards just to confirm zero after struggling at distance (windy). I was shooting over bare dirt, prone, sunny. Mirage was significant. Both groups were .4ish mils low at 100 yards.

Did you adjust your parallax adjustment, when you went from "distance" to 100 yards?
 

BBob

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Does mirage generally cause your impacts to be lower?
Generally higher. Mirage will make it look like the aim point is higher than it actually is so if you aim at the false elevated image you will hit high on the actual target. If you watch carefully you can see the aim point twitch up, back down, side to side as mirage varies. It’s where the old saying “suns up, bullets up” comes from (the effects of mirage).
 
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Jimbee

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Did you adjust your parallax adjustment, when you went from "distance" to 100 yards?
6x and 3-9 swfa. Not sure if I adjusted parallax on th6x. Maybe just an anomaly. A 3 shot and a 4 shot group were both low.
 
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