I'd classify this as a survival or prepping skill, so ...

I've had this Master lock forever ... the kind you use on school and gym lockers.



* FYI - Imgur was having problems resizing and saving this image.
Had to copy it to my PC and upload a second time with correct size.   

So, I've stumbled across this lock every time I've gone through boxes and dresser drawers to search for/organize stuff.  Each time I have a minute, I'd go on YT and other sites looking for the next possible hack to get it open.  This was my daughter's lock, so I didn't have the combo indelibly etched into my brain from a decade of use like others I've owned.

FINALLY, after literally years of trying, I got it open!  The key, IMO, between this video and the rest is it's less about the mechanics and math, but more about the "feel."  I've had the right number for the first digit based on every other video.  The disconnect came from some videos doing a "guess" for the second and third numbers, finding the remainder after dividing by 4, then using that to figure out the second number.  Very convoluted and seemed to work for the lock in the video.  I think the process was tailored for the known outcome, not for a repeatable process that applies to other locks.  They even say "may not work for all locks."  More like, "Only works for the lock in the video."

Getting the right amount of tension on the shackle for the first number is easy.  Getting it right for the second number is trickier, but might only take a few tries to get it right.  The third number is a piece of cake.  Just stop the dial after 2 digits from the second one, then stop every 4 digits after that, and pull on the shackle.  You'll know when you hit it!

This video is 3 years old, so obviously it's been awhile since I last tried.  Props to the video maker and his easy-to-follow process.

Hope this helps others.

I tried that on an old Master a few years ago and got nowhere.

Many years before that, if you brought a lock into a locksmith, they could look up the combo.

I tried that on an old Master a few years ago and got nowhere.

Many years before that, if you brought a lock into a locksmith, they could look up the combo.

If you want to go through the hassle, you can print the PDF from Master Lock's site, fill it out, have it notarized (usually free at your bank/CU), and mail it along with a photo showing that the lock is not attached to anything.  Give Master Lock about 4 weeks, and they will send the combo for that lock based on the serial number.

I never cared enough to go through all that.  Plus, going the "hacker" route made it a challenge!   

I must have tried 6-7 different methods over the years, and this was the one that worked for me.  I probably repeated several of them, just to see if I was the weak link in the solution.

YMMV.

Lockpickinglawyer is a popular youtube lockpicking channel or bosnianbill.  Almost all masterlocks are crap and some can be picked open faster than using a key or combination.  Some gun safes are scary easy to open to, especially those cheep trigger locks.

I've switch to using Abus german locks lately.

Not masterlock, but...


And for the newer version:

In the football lockeroom, every locker had this type of lock.  The linemen couldn't remember their combo, so it was common practice to just hit it with the heal part of your cleated shoe and it opens after 2 or 3 hits.

Screwdriver and paper clip is all you need.

Screwdriver and paper clip is all you need.

Breaching charge or breaching round (shotgun) is all you need. 

Subtle CMO. Real subtle.