Know Thy Trigger

The feeling of a quality trigger is hard to beat. A short, crisp pull is unbeatable when needing to make that accurate shot while a quick trigger reset is beneficial for rapid follow-up shots. We all know what a good trigger feels like, but what is expected in a quality trigger? What benefit do you receive with an aftermarket trigger over a factory one? Those questions require lengthy discussion and debate and will receive some attention today.

Every firearm trigger goes through a process before it sends a projectile down range. There is a plethora of trigger types and designs on firearms: double-action, single-action, two-stage, single-stage, and so on. Each of those triggers, though, undergoes a process of movement from the first pull and every subsequent pull thereafter. For my purposes, I categorize the trigger pull into a series of steps: Pre-travel/slack/creep, the wall or shot break, overtravel, and trigger reset.

First and foremost, there is some debate as to whether you’re pulling or pressing a trigger. These words dive into the semantics of how our brains mentally process information through visual, tactile, or auditory means. For some, “pull” induces a subconscious link between a more violent action like jerking a rope or leash by pulling on it. For myself, I normally refer to the trigger “pull” as a trigger “press”. The pressing of a button is rarely a violent or abrupt action like pulling something. Thus, when I refer to a trigger “press,” it’s the same concept as the “pull” — but with more precise wording to describe the act.

Pre-travel or Trigger Slack

Most triggers have some kind of slack in them. Slack is best described as the progression of the trigger rearward during the trigger press prior to hitting the wall on the trigger. The wall on the trigger is the pressure felt prior to disengaging the sear on the firing pin to fire the shot. A striker-fired handgun, like a Glock, HK VP9, Springfield Armory XD, or Smith & Wesson M&P series uses a striker-fired design. Those triggers have a significant amount of pre-travel prior to firing the shot. The action of pressing the trigger on a Glock, much like a revolver hammer, cocks the striker towards the rear while deactivating internal firing pin block safeties. Thus, the trigger pre-travel is long.

1911 Single Action trigger, Smith & Wesson double/single action trigger, HK VP9 with striker-fired double action trigger, and Sig 229 Carry with single/double action trigger.
Triggers come in a wide variety of designs. From top to bottom: 1911 Single Action trigger, Smith & Wesson double/single action trigger, HK VP9 with striker-fired double action trigger, and Sig 229 Carry with single/double action trigger.

Pre-travel is not as significant or pronounced on single-action triggers — like a cocked revolver hammer. 1911 and 2011 handguns commonly have single-action triggers. These triggers are exceptionally short and crisp but require external safeties like a grip or frame safety due to the reduced (or non-existent) trigger slack. Firearms like a Sig 226 or 229, CZ 75, or Beretta 92 have a double-action and single-action design. The first shot fired cocks and releases the hammer while every subsequent shot cocks the hammer back into single-action for follow-up. As a result, the first trigger pull is different from every subsequent trigger pull.

The Two-Stage Trigger and Pre-Travel

Some triggers, like a two-stage trigger, are designed to have a preset amount of travel before the shooter hits the wall to break the shot. This two-stage design is found mainly in competition and precision rifle platforms. A Geissele two-stage trigger allows the shooter to impart several pounds of pressure on the trigger before it is staged onto the second stage when the shot is fired. This design, for example, allows a six-pound trigger to feel like a two-pound trigger.

The two-stage trigger makes for a less dangerous “hair” trigger by putting the first stage of slack at four pounds. The shooter is imparting four pounds of pressure on the trigger when they hit the second stage, which is six pounds. Thus, it only requires an additional two pounds of pressure to fire the firearm on the second stage. The trigger feels like two pounds but is really six pounds because the shooter already has the pre-existing pressure on the trigger.

Geissele two-stage AR trigger on the left and factory AR trigger on the right
The Geissele two-stage AR trigger on the left uses multiple sears to produce a lighter felt trigger press while the factory AR trigger on the right uses a single sear.

The Trigger Wall

While trigger slack is a common complaint for many shooters, the “wall” or point where the shot breaks off is equally important to a quality trigger experience. If the trigger “creeps” or has a significant distance prior to breaking the shot off, recoil anticipation enters into the equation. While the goal is to train to not anticipate recoil, it’s not a natural act to experience a 30,000 PSI explosion in your hands. A crisp break on the trigger gives a more consistent and accurate feeling of knowing when the shot will go off. There is some debate among firearms instructors as to whether you want to know when your shot will go off during the trigger press. That debate is beyond the scope of this writing and for another time. For me, I prefer the confidence of knowing exactly when the shot will go off during the trigger press.

Some firearms have awful triggers during the shot portion of the trigger press. Without naming names, there are some triggers where you feel the trigger bar grinding against the sear to disengage the hammer or striker. It’s not enjoyable to take up slack, hit the wall, and then progress through 3/8” of further travel waiting for the shot to break.

Most aftermarket triggers, like Apex or Zev, reduce pre-travel and have a crisper trigger break over the wall. Factory AR triggers are notorious for creep through the wall with little to no pre-travel. Triggers from Geissele, Timney, ALG Rise Armament, and TriggerTech provide reduced creep through the wall and make the trigger crisper and more consistent with what many of us expect out of a bolt-action rifle.

Overtravel and Reset

If using a semi-automatic firearm, an additional component of a quality trigger comes into the picture — overtravel and the trigger reset. Overtravel and the felt reset directly affect the amount of time between shots (e.g. split times). A quality trigger reset shortens the amount of distance a trigger needs to be moved to re-engage the sear for a follow-up shot. For example, early Smith & Wesson M&P triggers didn’t have much of a felt reset when letting the trigger out. Apex triggers and several other aftermarket offerings fixed this lack of felt reset. Furthermore, if the trigger travels rearward a significant distance after the shot is fired, it takes longer to let the trigger out to reset for the next shot. A shooter could, and should, train to be familiar with this reset and where it’s at. Removing unnecessary slack on trigger reset is an option with several different aftermarket options as mentioned above.

glock 19 trigger travel
The movement and travel of a factory trigger on a Glock 19. The trigger has several millimeters of movement to the wall followed by a noticeable amount of overtravel and return to reset the sear for the next shot.

Some firearms, like the Sig Legion series, Walther PPQ, and HK VP series have phenomenally short and positive trigger resets. If your firearm doesn’t have this and you find it hard to obtain a positive reset for fast follow-up shots, an aftermarket trigger is worth looking into. The Springfield Armory XD series was notorious for a long reset. Companies like Powder River offer trigger packages that shorten the reset significantly and provide a shorter trigger reset. Meanwhile, some guns are born with short trigger reset because they’re a single action design like a 1911 or 2011 series pistols along with other single-action firearms.

Caution About Aftermarket Triggers

Aftermarket triggers have a tremendous impact on the weight of pull, overtravel, and creep. There is a catch to making such modifications to a firearm — lighter “hair” triggers can be a liability for the shooter and others around them. A short, crisp, and light trigger has a point where the trigger is too easy to press and, consequently, discharge the firearm. This presents a risk for the shooter and those around them from accidentally discharging the firearm.

Some firearms have aftermarket triggers available for them that directly affect the firing pin block and its spring. For instance, a Glock has a firing pin block “drop safety” that prevents the firing pin from completing its full travel to detonate the primer. Some aftermarket trigger kits replace the block’s spring with a lighter one that reduces the weight of the trigger press but affects its ability to prevent a discharge if the gun is dropped.

firing pin block safeties of four handguns
Most modern pistols have a firing pin block safety. Modifications to lighten these does help with the felt trigger weight but can have unintended consequences by affecting the safety of the firearm.

An aftermarket trigger has benefits for the shooter and many are worth the money. When purchasing such upgrades, keep in mind what you intend to use the firearm for versus the trigger you’re putting into it. As a word of advice, the money spent on a match trigger for your defensive handgun may be better spent on some range time or a training class.

If you must enhance your trigger, don’t bust out a file and grinding tool. Spend the money on a quality aftermarket trigger. Filing on a trigger sear or polishing certain parts alters the hardness of the steel on the sear. Over time, the sear can wear down and no longer has the ability to adequately keep a cocked hammer engaged during use. Things like hammer follow (when the hammer follows the slide down and the gun doesn’t go off) or hammer drop (hammer slips off the sear due to a lack of engagement) are very real and many documented incidents exist of home gunsmithing gone wrong on firearms as a result. If you’re going to upgrade your trigger, don’t do it at home — buy a quality upgrade at a minimum. There are plenty of options available to give reliable and consistent triggers with better overall performance than their factory counterparts.

Tom Stilson began his career in firearms in 2012 working a gun store counter. He progressed to conducting appraisals for fine and collectible firearms before working as the firearms compliance merchant for a major outdoor retailer. In 2015, he entered into public service and began his law enforcement career. Tom has a range of experience working for big and small as well as urban and rural agencies. Among his qualifications, Tom is certified as a firearms instructor, field trainer, and in special weapons and tactics. If not on his backyard range, he spends his time with family or spreading his passion for firearms and law enforcement.

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