1911 Pistol Modifications - Actions
by Dennis L. Schrieber, Pistolsmith
Probably the most commonly requested work on any pistol is the Action Job. The action is no one single part of the gun but, includes all the parts from the trigger to the firing pin. Just changing a trigger or spring or stoning a part or two isnt enough. The action is really a system of parts, all working in harmony together to provide the feel desired and the safety required.
Lets start with the trigger. The trigger must be properly fit to the frame. This means that it must fall free through the frame under it own weight without any excess play. The lighter the trigger the harder this is to accomplish. Controversially the lighter the trigger the better the final feel. Triggers themselves, will be the subject of an article in the future. The installation of a 4 leaf sear spring can help to overcome some of the problems of trigger mass and is highly recommended for a competition grade action that is safe and reliable.:p>
The hammer and sear are at the heart of any action and the key to safety. Start with the hammer hooks, they must be exactly 90 degrees. If the angle is less than 90, you will have creep an a heavy pull. More than 90 degrees and the hammer can follow the slide an will be unsafe. The fit of the sear to the hammer hooks is very important. The face of the sear must be in full contact with the face of both hooks. After this is accomplished the sear can then be undercut. The ratio of the face of the sear to the undercut will determine the trigger pull. A properly fitted sear will show four contact points with the hammer. Another point to remember is that this hammer and sear set will only be mated for one frame. Frames do very both in spacing and in the alignment of the pins across the frame. In our shop, sear to hammer fit is done under a 25X microscope, its that important!
One of the favorite components for shooters to change is the springs. This is another area that is not to be taken too lightly. Two springs are associated with the action: the main spring and the sear spring. The sear spring should have all the contact edges stoned. This will help the too give that smooth feel and reduce wear. Care must be taken when bending the fingers to maintain their proper relationship to each other and to provide the proper tension to safely operate the firearm. The main spring to sized to balance the speed and force of the hammer fall against the weight of trigger pull. The standard is 20 lbs. and commonly range from 17 to 23 lbs.. Lighter springs are used mainly with those lighter components. Lighter parts, that are skeletonized or made of Titanium, will shorten the lock time. Lock time is defined as the time between the trigger pull and ignition of the powder charge. The heavier the spring tension the shorter the lock time and the heavier the trigger pull. Too overcome the use of lighter springs we can counteract with lighter parts. The lighter part will have less inertia and therefore will accelerate faster, thus shorting the lock time. A shorter lock time will help to improve scores in both bullseye and the action sports.:p>
Action work can provide the shooter with the feel and reliability that will enhance the shooting experience. Target shooting is a mental sport, anything that distracts the concentration will detract from the final score. A good trigger is important and safety is paramount. So, visit your favorite pistolsmith. Good shooting, keep it fun and keep it safe. Any comments or questions should be directed to Dennis L. Schrieber, Burnt Mill Smithing, www.burntmill.com or