BANG, SWITCH, BOOGIE
A NEW APPROACH TO SENDING ROUNDS DOWN RANGE
A new approach to sending rounds down the range.
To say that tactical shooters are passionate about their rifles is a gross understatement. That passion goes beyond the rifle as a whole and extends to each individual shooter’s choices of components. Various debates rage on: Which is better, piston or direct impingement? Is it called a silencer or suppressor? Which is essential, a flash hider or a muzzle brake? The list goes on. One such perpetual debate is what type of trigger – a single-stage or twostage – to use to make your AR send rocks down range.
The trigger is the shooter’s only direct connection to getting rounds on target. As such, the choice of what your nose picker uses to make the rifle go bang is a very personal one. With the growing number of companies putting triggers on the shelves, there’s one that’s offering a particularly different take on the design Mr. Stoner first dropped in to his industry-changing rifle: Triggertech.
Trigger Design 101
Before getting into how the Mississauga, Ont.-based company is reworking physics into an upgraded trigger design, let’s review the basics of AR trigger design.
At its most basic, the trigger is a lever that provides the mechanical advantage to overcome a great amount of friction to release the hammer and make your boom stick go boom. The actual sequence of events and physics resulting from a squeeze of the trigger are a more detailed interplay of various components, but for our purposes and allotted space, we’ll keep the physics to a minimum.
Single-stage triggers are the most common type found on off-therack ARS and rifles. In one single movement, hence “single stage,” the hammer (or striker) is released. Pulling a single-stage trigger starts the sear moving immediately until the hammer is released with a positive crisp break. Since the sear is in motion from the get-go, there’s little wasted movement, generally little take and a short reset.
“THE TRIGGER IS THE SHOOTER’S ONLY DIRECT CONNECTION TO GETTING ROUNDS ON TARGET.”
A single-stage trigger is very efficient when shooting fast and in situations when speed is a prime concern.
Two-stage triggers have, you guessed it, two movements. The first lighter movement brings the trigger to the noticeable wall. After this “break wall,” the trigger functions much like a single-stage trigger, applying consistent pressure until the sear break and the hammer rotates forward and bang, rounds go down range. The first stage lets the shooter know when the hammer is about to be released. Knowing when you are about to break a shot is critical feedback when shooting for precision and when shot timing is critical.
Another advantage of a two-stage trigger is in its inherent safety. When in the fire position, it’s less likely to have an accidental or negligent discharge when there’s an extra step involved in breaking a shot. However, because of the initial take up of the first stage and a longer reset, a twostage trigger, in theory, is slower than a single stage. The popularity of twostage groups is increasing, even in the speed-shooting crowd.
Trigger and Sear
Those are the high-level differences between single-stage and two-stage triggers. But, like I said above, it’s a little simplistic to say that you merely pull the trigger, the hammer drops and the gun goes bang. Let’s dig down a level and talk about the relationship between the trigger and sear when breaking a shot, and what happens to that relationship as we adjust for trigger pull length (not to be confused with length of pull), and pull weight. Both weight and pull length affect the amount of friction between the trigger and sear. If you look at a standard trigger group, you’ll notice that the sear and hammer overlap. Springs within the assembly apply a tremendous amount of pressure to this overlap, resulting in two types of friction that must be overcome for the gun to fire. Static friction keeps the hammer from moving against the sear preventing the hammer from rotating forward. Kinetic friction resists the movement of the sear against the hammer.
Decreasing the overlap shortens the pull distance and decreases friction between the sear and hammer. Increasing the hammer/sear overlap will increase friction and the distance the trigger has to travel to drop the sear. This travel distance is also known as creep. In a perfect world you want as little creep as possible to have a crisp, clean break. The concern, however, with having so little purchase between the sear and hammer is that the static friction might not be enough to keep the hammer from rotating forward should the rifle be dropped or the trigger otherwise moved. To prevent this we can either increase creep and/or increase the pull weight, a delicate balance between safety and performance.
Walking the razor’s edge between performance and safety means mitigating friction. That’s where the Canadian magicians at Triggertech come in. It seems that the folks in the Great White have a pretty good grip on the physics. Specifically Triggertech’s design uses a stainless steel roller bearing between the sear and hammer to nearly eliminate the friction between these two surfaces. There’s a very good reason they call it Frictionless Release Technology, or FRT for short.
To understand how this makes a difference in reducing friction, imagine pushing a large concrete block across the street. It takes a considerable effort to overcome the friction between the street and the block. But when you put wheels on the block, the effort to get it across the street is significantly reduced. It seems pretty obvious.
With a roller bearing between the sear and hammer, there’s a near frictionless trigger action. There’s no need to play around with how the hammer and sear overlap each other. With the relationship of the sear and hammer remaining consistent and only the pull
weight to be concerned about, safety is no longer compromised for the sake of performance and creep can be consistently kept to a minimum. Heavy pulls are smoother and light pulls are safer because sear/hammer engagement has remained consistent.
Additionally, because there’s virtually no frictional force to overcome, the trigger is not dependent on mechanical advantage to move the sear. The result is a marked reduction in creep. The comparison has been made the trigger feels more like a custom 1911 trigger. Eliminating creep also creates less wear and tear on the trigger group as a whole.
Another important part of trigger group function is how the trigger resets. Again, friction and overlap are the enemies of a defined reset. After all, it’s no good to make the rifle go bang if the follow up shot is slow and sluggish, waiting because the trigger is caught up getting to its original forward position. The FRT also reduces friction on the way back, allowing for a smooth and defined reset.
A key feature of many drop-in trigger groups is the ability to adjust the weight of the trigger pull. Usually this is done by turning a set screw tighter or looser to get the right pull. Sometimes it can be a shot in the dark determining exactly where your pull is set.
Triggertech takes the same principal found on scope turrets and applies it to the set screw. When turning the screw to adjust the pull weight, you move through a series of clicks. Each positive click adjusts the pull by 2 ounces, with a high mark of 5 pounds and a low of 2.5 pounds (Model: Adaptable AR Primary trigger) that gives the shooter 80 points of adjustment.
I can hear the questions starting to pop the synapses in your gray matter. “Sure adding a couple of parts may add to the overall performance, but that doesn’t mean much if it’s not going to last.” Triggertech’s test data shows that after 50,000 shots, there was no noticeable change in movement in the trigger pull or change in the pull weight. But that’s their data. What about real world?
Performance On Target
I dropped two different Triggertech triggers into my SMOS GFY16 (smosarms.com) and ran through a couple thousand rounds. Though not nearly as many as the company’s tests, I thought it would give me a good idea of the group’s durability and performance, especially because I didn’t clean the rifle during the process. In a nutshell, the groups performed as advertised. The performance was consistent with a smooth pull even when carbon was almost flaking off of the bolt carrier group.
As much as I don’t want to, I get excited about the newest features and hyped up doo-dads to throw on my rifles. Generally, however, I’m underwhelmed and realize that I’ve once again bought into the marketing hype. With these triggers, however, I got exactly what I was told I’d get and a little more. Don’t take my word for it. After all, triggers are extremely personal, but Triggertech is definitely worth the consideration. TW
“KNOWING WHEN YOU ARE ABOUT TO BREAK A SHOT IS CRITICAL FEEDBACK WHEN SHOOTING FOR PRECISION AND WHEN SHOT TIMING IS CRITICAL.”
Trigger styles are very personal things. For me a flat blade adjustable trigger fits my needs.