If a minimum of one of the pins is cut for full length, then a bump key won’t open the lock. You can tell if your key has that one magic pin because the cut on the key will extend all the way to the bottom of the key. Bump keys work on many locks but definitely not all.
Medeco locks have a good reputation but they aren’t like a military armory padlock. But then again, good locks only keep honest people honest.
For survival, everyone should buy and learn to use a clicker [lock opening] gun (These cost approximately $50) as well as a good German surplus wire cutter. if you have to take shelter in an abandoned building, you can unlock the door, go in and re-lock the door. Keeps you a lot safer and makes it a lot more private. (Read “less noticeable”). [Comments on other topics deleted, for brevity.] Best regards to all. – The Army Aviator