Combination masterlocks are great because the key can't be lost or stolen because the key is always kept in your head. Until you forget it. If you utilize a lot of locks for storage units and a few bug out locations, it also gets difficult to keep all of these combinations sorted out in your head or on paper. With the trick below, that's no longer an issue.

This is an excellent trick for anyone who utilizes Master locks on a regular basis. In a post-SHTF world, this is also a valuable tool because it'll allow you to get into abandoned buildings that utilize this lock.

Of course, you want to be sure the building is completely abandoned because you don't want to get caught breaking and entering in a wild west world. For urban survival, though, this is certainly a valuable trick.