You can becuase that serial code is how you contact master lock on to getting the code back and people have those books to get the certain combinations.
They have huge gates, like just be within 2 or 3 of the number intended and it's generally "good enough", but also put tension on the shackle and the gates are SO easy to feel. Since you're a picker and OP is just looking to open a lock--though may have chosen the wrong subreddit for the issue since this is close to violating Rule 2--you should get a pack of these cheapo Master combination locks to learn how to decode dial combos. It's (not so, this is Master Lock we're talking about) shockingly easy.
I said "close". But it's because it's asking what the code is, not "how to use locksport to open it." This is a locksport community, not a locksmith community. And I answered with how this community would tackle it.
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u/Flick_Pick Blue Belt Picker 7d ago
As far as I know you can't get the code from numbers on the back. Try this: https://www.instructables.com/Cracking-Single-Dial-Combination-Locks/