Occasionally however, they’re a little over zealous. A little too much of the wrong type of lube on a sub-zero morning and your firing pin or other moving parts may freeze solid. Oil lightly, or better yet, use graphite or other non-liquid lubricants.
Cold isn’t usually much of an issue with modern cartridges and smokeless powder. However, it can wreak havoc on black powder or its substitutes. Actually it’s not so much the cold as the drastic changes in temperature, which cause condensation that can render your powder weak or useless.
There are several steps you can take when muzzleloading in cold weather. The most important is to avoid exposing your gun to rapid temperature changes. At the end of the day, put your gun in a padded case, even before loading it into your (heated) truck. If you can do so safely, store it outside, in a locked vehicle or un-heated building.
Cold can also be a bane to optics, particularly when combined with moisture. And that moisture can be as minimal as your own breath. Exhale on your scope at the wrong time and you’re effectively blind.
At the very least you should always carry a lens cloth and/or lens pen with you. You might also carry a handkerchief or scrap of material. Absorbent material like cotton will work far better than the moisture-wicking materials you should be wearing in cold weather. You can also treat your scopes and binoculars (and glasses if you wear them) with an anti-fogging solution. As with your muzzleloader, you should also avoid exposing your optics to rapid and dramatic temperature changes.
Cold weather only adds to the list of things that could go wrong in the field. Fortunately, there’s much you can do to overcome at least some of them. An ounce of prevention is worth a pound of wet powder.