Extreme Lubrication for High-Friction Parts Reliability drops and parts are damaged when lubrication fails. Protect your firearm with Montana X-Treme Gun Grease, an all-purpose lubricant that will not breakdown under extreme temperatures. With a range of -50˚F to +600˚F, this anti-friction, heavy load bearing grease stays where applied and does not harden. It is virtually unaffected by water and corrosive moisture, which makes it ideal for weatherproofing metal.