I don't think it fouls at all, based on my usage. But, I clean between each shot, and don't even attempt to fire 2 or more shots without cleaning. This is not a petroleum based oil. Its comes from a bean grown on a desert plant, and is more a vegetable oil than petroleum. I used it for years to oil the working parts in my locks, and never had it congeal, or gel, or cloud. I did wipe out the locks after each shoot, as a standard cleaning practice, and then re-oiled my lock with Jojoba oil. I also used it for a time in my .45 auto, on the slide, and it works as well in that pistol as it does in my MLer. Because of the expense of the oil, I stopped using it in my pistol, and saved it to use in my locks.
JoJoba is a fine oil. Oh, I have never really tested it in subfreezing weather. Timing mostly. I suppose the easiest way to test it would be to put the oil on a lock, put the lock in a plastic bag, and put in the freezer over night. If the oil still performs, after being at 10 below zero for 8 hours or more, I think its safe to assume its a pretty good oil. There are oils ( synthetic) designed for use in truly subfreezing temperatures, and work at -60 degrees and even colder. They were developed for use in Aircraft Engines, and if I were planning a hunt in winter in Alaska, or the NW Territories, I would not hesitate to find some of the stuff, and use it. I don't believe such an oil or lube is necessary in most of the lower 48 states. To test Jojoba oil at these extreme Temperatures, I would need to find someone in the Chemistry or Physics departments here at the University that is using Liquid Nitrogen to freeze items, and put a test sample in their freezers. There are now private industries that are doing their own cryogenic treatment of metals, so look around if you are wanting to test this oil for extreme temperature usage.
