September 23, 2010
One of the most productive changes we can make to any gun is to give it a crisp, safe trigger that is reasonably light. The 1911 is a prime candidate, but the problem is that few of us have the training necessary to do it right, and unschooled filing on hammer hooks or stoning sears is an invitation to disaster. But if you can detail strip the pistol, it is certainly possible to install a set of matched parts such as those sold by Cylinder & Slide Shop.
Perhaps the most difficult part of the job is removing the hammer strut from the old hammer and putting it into the new one. I don't know why it is, but manufacturers seem to strive for a tight press fit with the hammer-strut pin, and you need a properly sized punch to drive it out. This is where a bench block comes in handy. It can also be a challenge to get the pin started straight in the new hammer (1). I use a pair of needle-nose pliers to hold it straight for a gentle hammer tap.
One little trick I use to get the sear and disconnector installed is to hold the two parts between thumb and forefinger (2) and then slide them into the frame with it turned on it's side (3). That way you can see when all the holes line up and use a small punch to hold everything in place. Then pull out the punch and, without shaking anything, put in the sear pin.
Next, install the hammer and new sear spring. Some of the kits come with a new mainspring, but I like to try it first without changing the mainspring (4). You can make some adjustment in weight of pull by bending the segment of the leaf spring that contacts the sear (5). That is the leaf (arrow) on the left, but try it first just as it comes.
Complete the assembly with grip and thumb safeties. Use a small punch inserted behind the thumb safety to depress the plunger spring and use your thumb to push the safety in as the punch is withdrawn (6). Both safeties need to be checked for proper function. To test the grip safety, simply pull the trigger without depressing the safety. The hammer should not fall. With the thumb safety "On," depress the grip safety and pull the trigger. You should not be able to see or feel any hammer movement. Next release the trigger and flip the safety down. The hammer should not fall. If the pistol fails either of these tests, it probably would have before you changed the trigger parts, and it will almost surely need a new grip safety or thumb safety.
When you install the thumb safety for the first time, it should slip in without difficulty. If it doesn't, or if it is very hard to move, odds are that the safety is hitting the back of the sear. Try working the safety up and down a few times; it will usually leave a mark on the sear to show where it is making contact. One gentle stroke there with a file may be enough, so repeat the trial process until the safety moves with moderate effort. It is easy to take off too much and ruin an expensive sear, so make haste slowly. Continually repeat the safety check because the thumb safety won't work if you've taken off too much. Most of the time, everything will drop right in without the need for any further work.
Depending upon the type of kit you have, you can get a crisp, safe trigger from 31/2 to 5 pounds (7).
Time: 30 minutesCost: $115-$180List of materials: Cylinder & Slide Drop In Trigger Pull Set, 1/16- and 1/8-inch punches, small hammer, bench blockDifficulty level: Moderate