It is a Sargent & Greenleaf lock on a Browning safe (yes, I did not cheap out on the safe), and here are the detailed directions for opening such a lock that I found through the miracles of the Internet:
Clear the lock by turning the dial clockwise, a time or two will do. You can stop at zero if you like or go on past slightly, it doesn't make a difference on mine.
1st number - turn counterclockwise & past the number 3 times, stop on the number on the 4th turn
2nd number - turn clockwise past the number twice, stop on the number on the third turn
3rd number - turn counterclockwise past the number once, stop on the number on the second turn
4th number - turn clockwise until stoppedI was apparently not doing enough counterclockwise turns on the first number, or perhaps I was not clearing the lock in the first step before trying the rest.
Needless to say, I have found a way to have the numbers and instructions readily but stealthily available.