Cold Weather Impact on Ballistics – Fact or Fiction?

Ron Spomer |

img_4186_copy

As a general rule you don’t need to be concerned about this for general hunting until temperatures dip well below zero. And even then the differences may not be enough to cost you a hit inside of 300 yards. But the only way to determine this for certain is to test fire your rifle and your ammo in the conditions you anticipate. If you’re planning to hunt coyotes or foxes at 10-degrees below zero, go to the range at 10-degrees below and shoot paper at 200 and 300 yards. Do your bullets land appreciably lower than they do at 50-degrees? Watch for increased wind deflection (drift,) too, because a slower bullet not only drops more than a faster one, but deflects more in the wind.

So, with factory ammunition, follow Ronald Reagan’s advice: trust but verify.

Another cold weather threat is a dirty rifle freezing up. This is usually the firing pin/spring, one gunked up with old oil, carbon fouling and dirt. Keeping your rifle clean should prevent this. Learn how to strip your firing pin. Otherwise, clean things with one of those spray degreasers. Lube moving parts after this with light oils specifically formulated to handle extreme cold. Dry lubricants also work.

Something you might not consider, but should, is rifle fit. After you’ve donned the layers of fleece, wool and insulated parkas you’ll likely wear in bitter cold, your rifle’s butt stock may be much too long for a proper fit. With most guns, the fixes for this aren’t easy. If your stock doesn’t have butt spacers for lengthening and shortening, you’ll have to cut some of the stock off or learn to handle the excess length of pull. I’ve always done the latter. Practice this with your heavy gear on and you’ll soon learn to compensate for the extra reach needed to properly cheek the stock and reach the trigger. This won’t be your most comfortable shooting setup, but accurate enough for the few sub-zero days you’ll likely hunt.

If you’re a citizen or longterm visitor to bitterly cold regions, you’d be smart to have a stock shortened for this work. Laminated wood aftermarket stocks sell for $60 to $125, a reasonable investment. Trim the butt no more than 1/4-inch at a time and test the fit after each slice. Save them in case you determine later that you were a bit too eager with the initial chopping. The finished stock won’t look too classy, but if you shoot it more accurately, good enough.