Cold weather doesn’t just freeze your fingers—it can freeze up your ammunition’s performance too. Powder burns slower in subzero temps, velocity drops, and bullets that usually fly flat start acting sluggish. When you’re hunting in deep snow or glassing a ridge in a blizzard, those changes matter. Some calibers are more sensitive to temperature swings than others, and while they might perform fine in a mild fall hunt, they lose their punch when the mercury drops. If you’ve ever watched a deer shrug off what should’ve been a clean hit in freezing weather, you know exactly what I mean. Here are the calibers that suffer most when the cold takes over.
.243 Winchester
The .243 Winchester is a popular deer round, but in extreme cold, it can drop in velocity faster than you’d expect. Its small powder charge and light bullets don’t handle dense, frigid air well. The result is less expansion on impact and more wind drift over longer distances.
Cold powder burns less efficiently, so you might lose 100–150 fps without realizing it. That doesn’t sound like much until you see your point of impact shift or watch a marginal hit turn into a tracking job. In snow country, hunters often find that their .243 loses the sharp performance it shows on paper. It still works, but in bitter cold, the margin for error is small, and every foot per second counts.
.22-250 Remington
Few cartridges are as fun to shoot on a warm day as the .22-250, but in subzero weather, it can fall apart fast. The powder blend used in many factory loads isn’t designed for consistency in extreme cold. Velocity loss is one thing, but the real issue is inconsistent ignition, which can turn tight groups into shotgun patterns.
When you’re trying to hit coyotes across a snowy field, a 200-fps swing between rounds can throw everything off. The light 50- to 55-grain bullets also lose energy fast in the cold, thick air, so even a perfect shot doesn’t carry the same punch. It’s still a flat shooter in moderate conditions, but when you’re deep in a winter setup, the .22-250’s precision edge starts to melt away.
.270 Winchester
The .270 Winchester has a long reputation for flat shooting, but even it isn’t immune to cold-weather performance loss. The larger case means more powder that can slow down in freezing temperatures, leading to a noticeable drop in velocity. With 130-grain bullets, that can translate to lower expansion and reduced energy on target.
Hunters in northern climates often notice that their zero shifts when the thermometer dips into the single digits. Combine that with denser air and a slight change in trajectory, and you could end up missing high or low at longer ranges. The .270 still gets the job done, but if you’re chasing elk or mule deer in the snow, you’ll want to test your loads in the same conditions you plan to hunt in.
.300 Winchester Magnum
You wouldn’t think a powerhouse like the .300 Win Mag could struggle in cold weather, but it can. The large case and slow-burning powders used in many factory loads are sensitive to temperature shifts. When that powder cools down, ignition can get inconsistent, especially with older ammo.
The result? A round that kicks like a mule but doesn’t deliver consistent velocity or tight groups. In deep snow, the heavy bolt and long barrel can also make it harder to handle. Sure, it still hits hard—but if your shot placement is off because the round slowed down or printed differently, all that power doesn’t matter. The .300 Win Mag thrives when it’s tuned right, but in frigid weather, it takes more maintenance and testing than many realize.
6.5 Creedmoor
The 6.5 Creedmoor has earned a loyal following, but it’s not flawless in cold weather. With lighter powder loads and a reputation for efficiency, the cartridge depends heavily on consistent powder burn. Drop the temperature below freezing, and you can lose velocity and experience erratic ballistic performance.
When you combine that with the sleek, high-BC bullets it uses, things get interesting. The Creedmoor will still group well, but terminal performance drops noticeably at longer ranges when impact velocity dips. On elk-sized game, that can make the difference between a clean kill and a long tracking job. It’s not that the 6.5 fails outright—it just requires high-quality, temperature-stable ammo to perform like it should when it’s bitter cold.
.25-06 Remington
The .25-06 is a speed demon in fair weather, but cold temperatures steal that edge fast. Its long, overbore design relies on hot-burning powder to push light bullets at extreme speeds. When the air cools, that powder doesn’t burn as efficiently, and the cartridge loses velocity and energy downrange.
Hunters who take it into the high country or the frozen plains often report erratic groups when the temperature plummets. Even with handloads, keeping consistency takes work. The .25-06 can still anchor deer cleanly, but when you stretch it in deep snow or take a 300-yard shot in 10-degree air, it doesn’t deliver the same confident results you’d see in October weather.
.204 Ruger
The .204 Ruger is a laser beam under perfect conditions, but it’s notoriously touchy in the cold. Its tiny case volume and lightweight bullets mean every bit of velocity matters. When powder temperature drops, you can lose 200 fps easily, and that kills the flat-shooting advantage the .204 is known for.
On top of that, the thin bullets lose energy quickly once they start punching through dense, cold air. Varmint hunters often find that their hits don’t anchor coyotes or foxes the way they do in warmer conditions. It’s still a fun and accurate round, but if you’re winter hunting, bring a backup caliber that carries more mass and isn’t so temperature-sensitive.
7mm Remington Magnum
The 7mm Rem Mag’s power and range make it a great western cartridge, but its large powder charge makes it vulnerable to cold-weather shifts. The slow-burning powders often used in this cartridge don’t always ignite consistently in freezing temperatures, especially if your ammo has been sitting in a cold truck overnight.
That inconsistency can lead to vertical stringing on target and unpredictable energy delivery at range. Even a small velocity drop can mean less bullet expansion at long distance. Many guides in northern regions prefer cartridges that are less sensitive to temperature for this very reason. The 7mm Rem Mag is still a fine round, but when snow’s falling and your brass is frosty, it’s not as reliable as it feels in mild weather.
.223 Remington
The .223 Remington is a versatile and accurate cartridge, but cold weather highlights its weaknesses. Light bullets, small case capacity, and temperature-sensitive powders make it less dependable when the mercury drops. You’ll notice more drop, less energy on target, and sometimes sluggish cycling in semi-autos.
When hunting small game or coyotes in the snow, this can translate to erratic hits or runners. The .223 performs great in moderate climates, but in true winter conditions, it loses energy fast beyond 200 yards. It’s a fun caliber to shoot and cheap to feed, but if you’re braving deep snow and freezing temps, you’ll probably wish for something with more case volume and better cold-weather consistency.
.300 WSM
The .300 Winchester Short Magnum can struggle in cold weather more than you’d think. Its short, fat case design makes it efficient under normal conditions, but when the temperature plummets, slow-burning powders don’t always reach full pressure.
That means erratic velocity and poor ignition consistency. Add that to stiffer recoil in cold hands and a heavy bolt lift when lubricants start freezing, and you’ve got a recipe for frustration. It’s still a great performer in moderate weather, but when it’s snowing sideways and your rifle’s coated in frost, the .300 WSM can feel unpredictable. Most shooters find it works best with handloads tuned for cold-weather burn rates.
.257 Weatherby Magnum
The .257 Weatherby Magnum is a lightning-fast round known for flat trajectories, but cold weather takes away its biggest advantage—speed. It’s a classic overbore cartridge, meaning it relies on hot-burning powder and tight tolerances. When those powders cool off, they lose efficiency fast.
The drop in velocity can affect both accuracy and bullet performance. That sleek 100-grain bullet might start out at 3,600 fps in warm weather but drop several hundred feet per second in extreme cold. The result is less expansion and lower energy at impact. It’s still a capable round, but it’s one you need to handload carefully if you plan to use it in frozen conditions.
6mm Creedmoor
The 6mm Creedmoor shares many of the same cold-weather weaknesses as its bigger brother, the 6.5. With its lighter bullets and efficient powder load, any temperature shift changes its ballistic consistency. In subzero air, velocity loss is noticeable, and at long ranges, the round’s wind drift increases sharply.
In hunting situations, this means less reliable expansion on game and more margin for error when it comes to holdover. It’s a tack driver in warm weather, but when you’re glassing elk across a snowy basin, you’ll find it less forgiving. If you’re heading into cold country, the 6mm Creedmoor belongs back at the bench, not in your pack.
.22 Hornet
The .22 Hornet has always been a nostalgic favorite for small game, but it’s not a fan of winter. With its tiny case and low-pressure loads, even minor drops in temperature have a big impact. Powder burns weakly, ignition can get inconsistent, and velocity loss can exceed 200 fps.
That drop translates directly into poor terminal performance, especially on coyotes or foxes. The Hornet shines in mild climates, where its low recoil and soft report make it fun and effective. But once the air turns dense and cold, it turns into a popgun fast. If you’re planning winter predator hunts, you’ll want to leave the Hornet at home and grab something with a little more energy behind it.
*This article was developed with AI-powered tools and has been carefully reviewed by our editors.
