AK-47 is the best winter gun. V3 gearbox, and the design of the upper and lower reciever is pretty good so as snow has a hard time entering the inside (opposite is true with armalite ie.. ejection port cover). As well, you can take off the upper reciever plate and jam those hot hand warmers in to warm up your mechbox. As well, the selector switch is huge, the magazines/mag catch is huge, all easy to operate with gloves on. I used AK in the winter and it's very nice.
"Hokey religions and ancient weapons are no match for a good blaster at your side" - Han Solo
Commanding in Airsoft