It gets -40 here too occasionally (very rarely) and I never had any such problems with any of my firearms in the cold. I don't go out shooting much at those temps however, but I do have firearms in the truck bed held in clamps on the roll bar, and I have used them to kill coyotes and sometimes a cow if they needed to be put down. I use Mobile 1 full synthetic 90% mixed 10% ATF for all my guns. I have not found anything that works better so far. From as cold as it gets to as hot as it gets in Wyoming, my guns have always worked. Any guns that I'd worry about are not guns I keep. The one that gets the most "outside carry" is an AK47 and it's been 100% reliable in every case I ever fired it. No jams, no misfires and no malfunctions of any kind ..........ever.
When I was a younger man (much younger man) I was a Marine in Force Recon and we did train in ALL KINDS of conditions. The coldest place I ever trained in was north of Ft Greeley in a combined Army, Air Force and Marine Corp operation, or the time we cross-trained with the Canadian Army in northern Yukon. We fired M60s and M16s and the Canadians fired MAG machine Guns and FALs (C1s I think they called them) It was early February north of Ft Greeley, and it was December/January with the Canadians. Keeping the weapons dry lubed was important, but no breakages were reported that I know of. In Yukon I don't know how cold it was, but it was going from -55 to -67 in the Ft Greeley Op. It was about the same in Yukon.
So the idea that the guns would break is not something I would tend to believe. All of them had plastic stocks, hand-guards and grips. And our M16s were made of Aluminum too. If you get them wet from heating up and melting some snow on them it's important to get them blown out so they don't cool and clog with ice. So using weapons in such cold conditions is something you have to learn about, but breaking them was not what we saw. I never did anyway.........
Lubes were used but their main function was to keep the ice from adhering. The Canadians brought a cold weather oil which I think was an automatic transmission fluid. A light coat and the ice could be shoved off the metal. It would not grab the steel. The US Army had some kind of cold weather lube, (not LSA bus something with 3 letters. I can't remember what it was called now) and it seemed to work somewhat, but not as well as what the Canadians give us. One Candida soldier told me it was not something made for firearms, but was what they got from their truckers. It was pink in color.
Lubricant Arctic Weight (LAW)
