Trigger and Ignition Parts
Equally important as having a good set of sights that work well for your vision, a manageable trigger pull is of key importance to making accurate shots. The desired effect is to be able to fire an accurately aimed shot and not pull it off target because of a heavy, creepy trigger pull. You don't need a trigger pull set at 1.5 lbs. with "zero take-up and over-travel" characteristics, that will need to be re-done every competitive season or two. That sort of trigger pull is fine for a serious competitor at the Bianchi Cup, or the USPSA Nationals, but has no business on you self-defense gun. A clean breaking 4 to 5 pound pull will let you fire those accurate shots and will last a life time, with a little care.

Triggers
The point of contact between you and the pistol's ignition system is the trigger. I offer my Extreme Service trigger, which I consider to have the most desirable blend of design features available. My triggers are made with solid aluminum shoes that are oversize in height, available in short, medium and long shoe lengths. Extreme Service triggers feature smooth shoe faces. Removing serrations and holes to access the adjustable overtravel screw from the triggers contact point with your finger allows your trigger finger to be free from chafe and rub points that can leave your trigger finger sore after a long day at a training class. The Extreme Service line of triggers also feature hardened stainless steel bows that are micro-polished to reduce friction. The fixed over travel stop prevents the possibility of the typical adjustable over travel screw creeping in and stopping your gun from firing. It is initially adjusted by filing from the tip until over travel is set correctly. Extreme Service triggers are available for both 1911 pistols as well as the Springfield Armory EMP and all are offered in either natural silver, or finished in IonBond’s black DLC coating.

You should learn to pick a proper trigger length for the size of your hand. It will help you regardless of what type of pistol you shoot. To see if a trigger length fits you correctly, stand in front of a mirror with an unloaded pistol in your firing hand. Assume the correct firing grip and place your trigger finger's first pad across the face of the trigger. Hold the pistol pointed toward the ceiling with your trigger finger about eye level. Look into the mirror and see if your trigger finger is laying flat across the face of the trigger (parallel with the floor) or if it's lying at an angle pointed slightly up or down. Ideally, you want to be able to pull straight back on the trigger without inducing any force toward the side. When the shot breaks, the trigger will continue to move rearwards until it stops. If you are pushing sideways on the trigger, you can easily force the shot off to the side when the trigger movement jerks to a stop. Pick a trigger length that allows your trigger finger to lay flat on the trigger with no tilt. If you have to err in choosing, lean toward too short, rather than too long. Unless you have really large hands, I'd suggest that you try a short.

Ignition Components
Many of the 1911 pistols in production today are sold with ignition sets that are of low-bidder quality. It is not worth doing a trigger job to them because you never know if it’s going to last or not. I offer three Harrison Design ignition sets made to my specs from high-grade tool steel by CNC and wire EDM machining methods to +/- .0005” tolerance, then polished and honed. They are hardened and heat-treated to Rc 53-56 to maintain their dimensions throughout their life. The hammers all feature beveled edges and deep serrations for thumb cocking. The sear and disconnector are made from the same materials and methods.

The Extreme Service ignition set features a slotted Commander hammer that is narrowed to avoid rubbing the slide or ejector. The Original Commander set features a traditional round-hole Commander hammer that is also narrowed and has beveled edges. The Retro ignition set features a spur hammer that is bobbed and raised to prevent hammer bite. It looks just right on a Retro Custom that is so popular now. The sides are narrowed and edges beveled like all of the Harrison Design hammers. While all of these parts come prepped, I take the trigger job a step further by machine-squaring the hammer hooks, polishing all surfaces to the proper angle for the individual pistol and setting up the springs and ignition system to have minimal necessary take up and over travel and a clean crisp break.

Springs are just as important a part of the trigger job as any other component. I use springs from The W.C. Wolff Co. for every trigger job and any time a firearms spring is due for replacement. For street guns, I prefer to use full power 23 lbs. Wolff hammer springs to assure reliable ignition and to aid in controlling the slide's velocity. For competition-only trigger jobs, I will use 19 lbs. springs from Wolff to aid in reducing the trigger pull to "match use only" weights. The Colt current production sear spring is my pick after trying everything on the market. They are consistent in quality, strength and durability and hold their tension settings forever.

The finished trigger pull
Trigger pulls have been described as "like a glass rod breaking" or "like an icicle breaking". What these folks are saying here is that a good, crisp trigger pull has the attributes of having no perceptible movement after take up and then breaking engagement with a reasonable amount of force required, allowing the shooter to hold the pistol steady, always in alignment with the target. After the engagement is broken, the trigger is only allowed to move the minimum amount necessary to let the hammer swing past the sear, before the trigger's rearward movement is stopped by the over-travel screw.

Let's break the trigger pull into three parts: Take-up, Breaking of Engagement and Over Travel and talk about each.

Take-up is the first part of the pull that you feel. What is happening is that you are taking up the slack between the trigger, disconnector and sear, prior to the trigger pulling the sear from engagement with the hammer. The measurable weight of this portion of the trigger pull is usually less than a pound. The design of the pistol requires that there be some .040" of travel in the trigger to allow for full engagement of the sear nose into the captive half-cock notch. There is often a good bit more pre-travel, which can be reduced to the minimum on competition-only trigger jobs. I'd prefer not to remove too much take-up travel on a carry trigger.

The next part of the trigger pull that you feel is the main effort of force required to make the sear's nose pull free from the hammer hooks. I set up my trigger jobs to have about .010" to .015" of engagement between the sear and the hammer hooks. You have to pull the trigger through this small amount of engagement to break the sear loose from the hammer hooks. The engagement surface angles and surface finish make this travel unnoticeable, feeling more like you are pulling against something that is unmoving until you put enough force against it to snap it in two (this is where the "glass rod" comes in). If you have poor surface finish or bad contact points or bad angles, you feel this movement in starts and stops, called creep.

The last part of the trigger's movement happens after the sear comes free from its engagement with the hammer hooks. When these two parts disengage, the trigger is suddenly turned loose to fly to the rear against approximately the same spring tension as was there in take-up. In a stock gun, the trigger's rearward movement is normally stopped by either the front of the magazine catch or the front of the arm on the grip safety. The trigger can usually travel quite a bit, before it stops, causing a sudden jerk in the gun. This jerk translates to the bullet striking the target wide of the aiming point. The extent of this inaccuracy varies from one shooter to the next. The fix is to fit a trigger equipped with an over-travel stop. This is adjusted to minimize the over-travel of the trigger because the sooner you arrest the trigger's free movement after breaking the sear engagement from the hammer, the less jerk is transmitted into the frame of the gun, pulling it off target. There is a risk of the over travel stop working against you, if the gun gets really dirty, through neglect, a spill in the mud, or some other ingression of debris. The over-travel stop should not be set too tight on a self-defense gun to reduce the risk of dirt, lint, or debris getting between the stop and the mag catch, keeping the gun from firing. One other thing to know is that once the gunsmith sets the over-travel stop; it does not need periodic adjustment by the end user.

Thumb safeties and how they relate to the hammer and sear
Thumb safeties come from the manufacturer with an oversize fitting point on the stud that blocks the sear's movement and keeps the sear from moving out of engagement with the hammer hooks. When a new safety is installed, it won't fit into the gun, requiring this fitting pad to be filed down until the blocking stud fits so that the sear can't be moved at all, yet the safety can be installed in the gun. So, in effect, the thumb safety is fit to a particular set of parts, the frame, pins, hammer, disconnector and sear. When some of the parts in this set are replaced or a trigger job is done, the relationship between the fitting point on the blocking stud and the sear may change. Sometimes a little more will need to be filed away from the existing fitting pad, sometimes it'll be just right and work as-is and sometimes it has to be welded up and re-fit to remove any clearance between the stud and the sear. The reason that I weld and re-fit is that the only other option is to replace the safety with a new part.