by jgor » 12 Oct 2008 19:08
This is called a false set, it's normal on locks with security pins. The most common security pin is called the spool pin, because a strip around the middle is cut out and it looks like a spool. When you get a false set, in other words the cylinder rotates noticeably but then stops, that means the middle of one or more spool pins is now caught at the shear line. At this point you need to identify which pins these are and push them the rest of the way up so the bottom lip of the spool is overcome and is above the shear line. The best way to identify which pins these are is to try pushing up on each pin, and the ones that start to push back against your tension are the ones trying to overcome that lip. What you want to do is keep pushing up on those pins, slowly letting off of tension, until they over come the lip and set the rest of the way above the shear line.
That's the technique in general. In my experience the Master 140 usually only gets one false set, so you'll probably only have to use this technique on one pin. However as you get into more secure locks with quite a few security pins, you can experience upwards of 3 false sets before you get it open.
Hope this helps.
