I am currently working on pin tumblers and I have noted a few things about this Masterlock that I need opions on.
OK, from the heading, you are attempting to pick a Master #140. These are four pin brass-bodied padlocks with a maximum of three top spools. You may have one spool, two spools, or you may have three.
Can you push the pins in too far? So that there are two pins in the shearline?
Yes, you can push the pins in too far, but you will never have two pins at the shear line in one stack. If you push a key pin too far, the driver will be above the shear line and the key pin will be partway across.
When I am picking with a feeler pick, the further I go along with the 4 pins, the more the lock rotates, however I haven't got it to go all the way. When I am unsucessful, I slowly reduce the tension and I hear one to four little clicks, is that sucessful picking?
Nope, successful picking is when the plug rotates and the lock opens. What you are encountering here are the spool pins. A spool pin is shaped like a cotton reel, with a reduced diameter in the middle. This reduced diameter allows the plug to rotate and trap the pin across the shear line, resulting in a false set pin. Further picking on a false set spool, will result in a counter-rotational force felt on the tension wrench.
Along with those, I need to understand the ideal tension amount. Should I apply so the lock turns as much as possible, or should I apply so that the lock moves half-way between its max lock turning position.
There are many descriptions as to how much tension is required, but the best IMHO, is to insert the key and see how much tension is required to turn the key itself. This is the maximum that should be used. Other methods assume the weight of only one finger on the wrench. When confronted by a padlock which has a return spring, sometimes this has to be taken into consideration when applying tension, other times, the spring is only felt once the pins are picked.
For a great reference material regarding starting to pick locks, download and read the MIT guide. Then read it again. Then again. Then practice whilst reading, practice more etc...
For a thorough description of pin states, visit
www.crypto.com and read the lock picking section.
HTH,
Mick