The mechanical pick gun is a popular tool amongst professional locksmiths, both because of its effectiveness and ease of use. In the basic design of commercially produced pick guns there is little variation, though quality will vary from model to model.
The device is spring actuated with a changeable needle and a trigger. When the trigger is pulled, the needle lowers while winding a spring, snapping back up when the spring is wound. There is a dial that controls the tension of the spring, allowing the user to adjust the amount of force applied to the needle. Illus. (needed) shows a mechanical pick gun produced by Southern Ordinance.
Though learning to use a pick gun is much easier than learning to manually pick, the act is not without its nuances. Many first time users of a pick gun are frustrated when it does not work, though often times this is a result of poor technique, rather than any other factor. There are several factors must be considered when using a pick gun.
The first, and most important thing to consider is the positioning of the needle in the keyway. It is imperative that the needle strikes all pins at the same moment. In order to do this, the needle must be held perfectly parallel with the bottom of the keyway. If the needle is tilted at all, some pins will be contacted before others. In this circumstance, the first driver pin will have already fallen back down by the time the last one has cleared the shear line. In order for the pick gun to work, all driver pins must be above the shear line at the same time, leaving nothing to obstruct the rotation of the plug.
The second aspect to understand is the amount of tension set on the dial of the pick gun. Because this controls the force with which the pins are contacted, it is very important to find the correct setting that will maximize effectiveness. Too little tension will not provide enough force to overcome the spring bias on the pin stack. The driver pins will not be able to clear the shear line. Too much force will increase the speed with which the pins move, narrowing the window of time in which you are able to turn the plug. The best approach to this is to start with the dial on the pick gun set to its lowest amount of tension. Try the gun several times and then make a quarter turn on the dial, increasing the tension only slightly. Repeat until the lock is open. Once you have found this setting, you will find that you will often not need to adjust this setting with many popular brands of locks. Occasionally some locks will contain stronger springs, requiring you to increase the tension a little, however once this lock has been opened the tension dial can be returned to its original place in preparation for the next lock. Some may find it usefull to use a permanent marker to make a mark on the dial and a corresponding mark on the housing of the tension can be easily reset if it needs to be changed at some point.
A third factor to consider is the tension that is applied to the lock. A standard tension wrench is used in conjunction with the pick gun, and much like manual picking, the amount and method of tension applied to the plug will have a tremendous effect on achieving a successful outcome. In theory, the only time you need to apply tension to the plug is the precise moment when the driver pins have all cleared the shear line, before they drop back down into the keyway. In practice, timing this can be exceptionally difficult. It has been found that an effective method is to click the pick gun repeatedly while bouncing the tension wrench at a slightly different rate, oscillating between tension and no tension. It is then just a matter of time – usually not too much time – before the two events happen at the same moment and the plug turns. Sometimes a lock will succumb within the first three clicks, and other times one could spend five full minutes pulling the trigger before the lock opens. Through the process, be aware of the position in which you’re holding the needle in the keyway. If needed, stop pulling the trigger from time to time and realign the needle by lifting it gently until it contacts the bottom of each key pin, and it is running parallel with the bottom of the keyway.
With practice you will find that a pick gun can be a very effective tool.