Unfortunately, as you are turning the key clockwise (for the Best family of cores), both shear lines can impression. It is not uncommon to have multiple markings, especially at the beginning of the impressioning process. I frequently am able to see most, if not all, of the pin locations. Some will mark better than others. Also, just as experience tells you more of what is going on inside the lock by what you feel through your picks, bet Oldfast will agree that your eyes get better at spotting and interpreting marks as you gain experience.
Also, I find I get more, and better, marks by tipping the tip of the key up, bow down, then tensioning the key, and lifting the impressioning handle (or vice grips) followed by releasing tension. Repeat 4 times. Then the opposite - key tip down, bow up, tension, and press down, followed by releasing tension. Repeat 4 times. I get pretty good marks, and more of them, especially for locks that only turn one direction, such as some padlocks.
To my eyes, the marks do not appear different whether it is marking for the operating or control shear lines. This is part of the difficulty I had in impressioning SFIC cylinders. You can attempt privelidge escalation while impressioning. That will be my next attempt at the American padlock that I have not succeeded in making a control key for. Just need to get a box-o-blanks so I have enough to make that trial. Most of the time these days, I only need one blank to impression a lock, but I remember the difficulty I had with the SFIC locks, and want to be prepared.
Since both shear lines can (and do) mark, and in both directions, I think privelidge escallation should be doable. While the key will not turn with mixed shear lines, the marks should at least be reduced when all pins are set, but at mixed shear lines. If I cut one bitting down by a step, just as when you accidentally file too deeply, the impressioning marks will start up again. Then I can file down more and see if the marks go away again, indicating either a master wafer or the other shear line has been found. Repeat for each bitting, and it should, in theory at least, work.
Much better at impressioning now than when I last worked with those locks, and will probably see and interpret marks better. Am also getting another piece of equipment for impressioning that may help a bit. Have played around with one that belongs to a lockie friend of mine, and it seems to be a pretty decent piece of equipment,
The tool is called Martin Pink's Impressioning Tool Kit. The video below shows and explains it, but does not demonstrate what you see, how well it is illuminated (with either white light or UV) or the magnification.
http://www.youtube.com/watch?v=6BK_hT6jul4Gordon
Just when you think you've learned it all, that is when you find you haven't learned anything yet.
Tue Mar 12, 2013 11:31 pm 
