The Firearm Blog has a write-up of a person who took some guns to a really cold place. It is definitely an interesting read.
Canadian Rangers used WW2 Enfields for similar reasons, and Danish and Norwegians did similar thing with their soverign patrols.
http://www.thefirearmblog.com/blog/2015/12/22/tales-of-an-adventurer-using-firearms-in-extreme-cold/
From: The Firearm Blog