Here’s any easy method for backing out the combination of a Master Lock. In a perfect world there would be 64,000 possible lock combinations (403). The construction of the lock prevents this from happening: sloppiness in the dial and the numbers are not mathematically independent. First step is to determine the last number in the sequence. You can then use that number to determine the other possible numbers in the combination. You will end up with about 100 combinations to try, but that’s far better than having to throw the lock out which I’m sure would happen if you had to try 64,000.
UPDATE: x04d sent in a video demo (DivX) (dead link) of how to open a lock in 2 sec. using a padlock shim.
UPDATE: The linked video above has long been dead. Check out our more recent Master lock post for an embedded shimming video
This method is not required, In fact most master combination locks have a huge flaw in design with there latch pin spring, applying a light impact on the side of the U-bar wile pulling on it will cause the latch pin to retract momentarily and open. Sad part is this method quicker then entering the known combination.
As for useing shim’s they will give indications of false entry.
[youtube=http://www.youtube.com/watch?v=ZfGKP8W1ZE4&hl=en_US&fs=1&]