How Does Cold Weather Affect Accuracy In Precision Shooting

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Cold weather can affect accuracy in long-range shooting in the name of external ballistics.

Many gun owners including hunters store their ammo and rifles in their truck or in the garage overnight while it gets super cold during the winter.

Well… Can you trust your rifle to be accurate when it’s time to shoot?

It is like rocket science if you decide to dig deep, but here are some few simple things you can take with you after reading this post.

How Does Temperature Affect Ballistics?

In physics, material shrink and expand under our naked eyes due to air temperature changes.

This change happens quite often, and that’s why engineers take that into account when designing cars, airplane, and rockets that can handle a wide range of temperature threshold.

  • Air temperature affect gun powder burn rate
  • Air temperature affect bullet trajectory by the change in the air density
  • Dramatic air temperature change affects bullet drop
  • The longer the range, the more significant temperature-induced difference in points of impact.

How Does Humidity Affect Bullet Flight In Cold Temperature

When air density increases, the bullet has more air resistance during flight. Humidity is basically the term used to describe the amount of water vapor in the air.

The humidity varies along with the altitude and temperature, so when the air is cold and the water vapor content stays the same, then the relative humidity will increase because colder air doesn’t require much moisture to become saturated as warm air.

humidity affects bullet speed

Higher humidity equal thinner air despite the common belief that the air feels thicker, which means the air is less dense. Therefore bullet travels easier and faster through the humid air.

Before I get too deep into this, I want to clarify that the humidity is not the biggest influencer on ballistics and can be ignored in most cases. So let me keep it simple so you can easily remember it below:

Cold Temperature & Constant Vapor Content = Higher Humidity = Slower Bullet Speed = Hitting Low On Target 

Even though that’s the fact, but the actual change in impact points are very insignificant from 100 meters up to 1000 meters.

Why Using A Ballistic Calculator Will Make Your Life Easier

Although humidity has the least influential of the three environmental variables, it still influences the bullet trajectory a little.

If you’re new to the long-range shooting, you will find out quickly that if you don’t have a way to gather data, then you will have a hard time hitting targets at long distances.

In layman’s terms the three biggest variables that the ballistic calculator takes into account at the sea level are:

  • Pressure
  • Temperature
  • Humidity

There are many ways to do it including the old school ways of testing on the range for hours, but it’s not the most convenient method.

The easier method is to use a ballistic calculator such as the Kestrel 5700 Ballistics Weather Meter that can link up with your smartphone.

I felt comfortable buying ballistic calculator on Amazon, and the price was even better than getting it at a local outdoor store without shipping or tax.

The calculator collects the important info which is the net effect of air pressure, temperature, and humidity to make your life on the range a lot easier.

Besides that, it can also correct for aerodynamic jump, spin drift,  Coriolis effect and much more to achieve accurate long-range shots.

To learn more about ballistics please check out this awesome guide on our site: 28 Weird External Ballistic Effects Explained With Pictures

How Does Temperature Effects On Rifle Zero

When the cold weather drop from 10F to -20F. I have to say my guns do get cool down faster, so that’s a plus. But what about accuracy?

How Cold Affects Barrel Accuracy

When it’s super cold outside, by pacing your shot so there is no significant temperature increase, then you can maintain a very high standard of consistency and accuracy.

Variation in barrel temperature can lead to various bullet impact points because a hot barrel will warp at least a little bit, and that’s just science. It all depends on how much and how quickly it warps.

The best way to tell if your barrel is accurate is to zero your impacts when fired through a cool barrel, the industry calls it “cold-bore zero”.

As a rule of thumb: fire slow enough that your barrel never gets too hot.

This is precision shooting, not dumping magazines!

How Does Thermal Expansion And Shrinkage Affect Rifle Accuracy

Thermal expansion is the change in shape, volume and area of matter in response to a change in temperature. Temperature is a monotonic function of the molecular kinetic energy of a substance. What the hell does this mean?

In layman’s term, an object depending on what material it’s made out of will expand or shrink based on temperature. Each material type has its coefficient of thermal expansion that engineers use to predict expansion.

Aircraft, railroads tracks, buildings, mechanical parts, door frames all have thermal expansion accounted for when they’re designed for fitting.

When you shoot a gun even in cold temperatures, the barrel will get hot no matter what, if not then it will get warm. Each time a shot is fired, the barrel melts and expands just a little bit that lasts a millisecond, and it can affect the accuracy if it gets too hot.

Can Riflescope Maintain Zero In Cold Temperature?

Unlike the rest of the gun such as the barrel, which experiences from hot to cold back and forth. The riflescope’s ability to hold zero is depended on its build quality and the mount, therefore, the temperature has no direct impact on maintaining zero.

The only thing that could be affected would be the adjustment knob feeling a little stiff to dial in the cold. That’s why buying a high-quality scope is super important, you can check out those long-rang scopes under $1000 here that a lot of professional shooters are using and I guarantee you get the best and will not disappoint.

If you’re the long-range shooter who wants to take everything into account for an accurate shot, then you might want to pay attention to this because it’s hard to isolate the test without proper lab equipment.

Let alone bullet weight, wind speed, wind direction, powder grain weight, and much more elements can deviate a shot. Most people are more concerned about optic lens getting condensation due to extremely low temperatures. The answer is it could.

Is Temperature Effect On Bullet Drop Neglectable?

Yes. So far I think the extremely cold temperature doesn’t affect accuracy that much up to 200 yards. If you’re doing medium range or close range shooting, it should not affect your point of impact as long as you have a quality optic and mount. Most importantly, check the temperature spec of your optic from the manufacturer.

Conclusion

Shooting a rifle accurately involves a lot of variables such as bullet weight, atmospheric temperature, distance, powder charge and much more.

It’s not rocket science, but you need to know the basics to get started.

The extremely cold temperature that significantly involves elevation and air pressure would definitely affect the ballistics.

  • Ambient air temperature has an inverse effect on air density
  • Air temperature affect gun powder burn rate
  • Air temperature affect bullet trajectory by the change in the air density
  • Dramatic air temperature change affect bullet drop
  • The longer the range, the more significant temperature-induced difference in points of impact.

How you mount the optic and how you zero it are super important because it’s the one thing you can control before other factors come in to play.