For most of the year while you’re out hunting or target shooting, the only weather you have to worry about impacting your firearm is the rain. Temperature is usually not a huge concern for many hunters and shooters, until you hit the late seasons deep into winter. When the mercury drops below zero and you’re out in the field or on the range, how cold weather affects firearms suddenly becomes a major concern for both proper function and performance. In this blog, we’ll discuss how cold weather affects firearms and what you can do to mitigate those impacts to stay in the field and on the range longer. 

Frozen Temps and Frozen Parts

One of the most common issues you will hear about how cold weather affects firearms is from semi-automatic firearms “freezing up” during extremely low temperatures. This can happen a couple of different ways, but the most common cause of guns freezing up and jamming is due to the lubrication that the hunter or shooter uses. Traditional gun oils can start to gum up or freeze during extremely cold temperatures, especially if you apply too much. This will cause the parts they are applied to, typically the bolt, carrier, rails, and other moving parts, to freeze up as well. As a result, your firearm may not cycle reliably or jam up completely if it is cold enough. 

When the temperatures get bitterly cold, make sure you don’t over apply your gun lubrication. Applying too much gun oil can make it take longer to dry, and more likely to gum up and freeze as a result. If your gun continues to jam up and malfunction, you can also try dry lube! Dry lube is a spray that dries very quickly after it is applied to the firearm. It is useful to ensure proper function in adverse conditions, and will not freeze up like other oils can. Keep a can with you on your next waterfowl or late season deer hunt and see if it can help make a difference!

Ammunition Effects

When frigid temperatures hit, you shouldn’t only be thinking about how cold weather affects firearms, but also how it affects ammunition. Colder weather mainly affects how the powder burns in ammunition whenever you fire your firearm. Ammunition that is colder will burn powder slower, and some powder may be left unburned in the cartridge. This slower powder burn causes less pressure to build in the chamber, resulting in lower velocity when your rounds exit the barrel. This lower velocity will have an impact on how your firearm performs ballistically, and its performance on target. 

When temperatures get colder, consider storing your ammunition closer on your person. Keep your spare ammunition in a jacket pocket or pouch that is well insulated to keep it warmer, rather than having it stored on sling loops or a stock sleeve. If you have a removable box magazine, you may also consider storing that in a jacket pocket as well if temperatures are extremely cold. You can also test out your ammunition in colder environments to know how it will be affected when it comes time to hunt or shoot in the cold. 

Ballistic Performance

Not only does cold weather have an effect on your ammunition’s powder burning, but it can also have an effect on the ballistic performance of your firearm and ammunition. Temperature and air density are two key factors that will impact the ballistic performance of any firearm. As the temperature rises, the air gets thinner, resulting in less drag on a bullet. The opposite is true when air gets colder. Cold air has a higher density, causing more drag on a bullet and lowering your point of impact at longer ranges. This effect can also be magnified by the lower velocities that can occur in cold weather. These changes in ballistics may not matter at shorter distances, but they can have a large impact if you are doing long range shooting or hunting in wide open areas where long range shots are common. 

You can utilize a ballistic calculator to help make up for these changes in ballistics as well. Ballistic calculators take into account relative humidity, temperature, and other environmental factors that can change drastically when it is bitterly cold outside. Plugging these factors into a calculator can help you make the adjustments you need to hit your target where you want to. If the temperature is vastly different than when you zeroed your firearm, you may also consider re-zeroing in the colder temperatures to get a better idea of where your firearm will hit on target at different distances. 

Fogging Up

Knowing how cold weather affects firearms isn’t just useful for knowing how your firearm will function differently internally, but also how outside parts are impacted as well. Using optics is common in both hunting and shooting today, and cold weather can affect those optics greatly. Scopes and red dot sights both can fog up in colder weather if they are placed near a source of heat, such as going into a heated blind or fogging from heat coming off your face as you are looking through the scope. It may be a good idea to keep a cleaning cloth handy in your jacket in order to quickly wipe away condensation that fogs up your scope or sight. If possible, you may also consider going with iron sights if you are shooting at closer range where optics may not be as necessary.

By learning how cold weather affects firearms, you can be better prepared for the challenges and changes you may face during a late season hunt or a winter trip to the range. Whether you're chasing whitetails through the woods or waiting patiently for waterfowl in the blind, having a reliable firearm that functions in all conditions is important. By keeping your firearm running smoothly and on target in the cold, you’ll have better and longer hunts and more enjoyable trips to the range, so make sure you know how to take care of your firearm when cold weather hits!