Types Of Trigger Mechanism For The Total Beginner

For new shooters, trigger mechanisms and all the terminology associated with them can get confusing. Trigger mechanisms really only vary among handguns, so we will be focusing on handgun triggers instead of long gun triggers.

Think of a trigger as turning the ignition on a car. It sets a chain reaction in motion, resulting in a bullet being fired. When the trigger is pulled, it trips a hammer or a firing pin. That engages either a firing pin or a striker rod, which hits the primer of a cartridge. That sets off the powder inside and sends the bullet out of the barrel.

We're going to go over the basic types of trigger action, touching on each of the popular trigger mechanisms as well as what you should know about each.

The Common Types Of Trigger Mechanism And How They Work

trigger actions

There are three basic types of trigger mechanism. These are found in virtually every handgun you're likely to come across, each performing the same basic function - casing a hammer or striker to impact the primer - but each accomplishing the task in a different matter.

Note, however, that semi-automatic pistols and revolvers are different designs and therefore have differing features.

  • Single action: Mechanically, it's a simple method. The trigger releases the hammer, striking a firing pin which in turn strikes the primer. A revolver will require the hammer to be cocked with each shot. A semi-automatic, however, is cocked by cycling the slide when charging the pistol. After each shot, the recoil will cycle the slide and re-cock the pistol. The trigger mechanism is simple, as the trigger trips the sear and causes the hammer to fall.

  • Double action: The trigger completes two actions — it cocks the hammer and then releases the sear, dropping the hammer which hits the firing pin which makes contact with the primer. Double action revolvers can be fired by making the long pull or by cocking the hammer for single-action operation.
    The trigger itself is hinged, as a longer travel is necessary to cock the hammer. As a result, the trigger pull is heavier and longer. Some see this as a safety function to reduce negligent discharge. Some find that a double action trigger improves accuracy because of its consistent trigger pull in each shot. Double action triggers and mechanisms break down further into two categories:
  • Double action only: double-action only pistols only fire in double-action mode, with the attendant long, hard trigger pull. DAO pistols, as they are called, will often enclose the hammer or firing pin inside the frame (for DAO revolvers) or inside the slide of DAO semi-autos. Some people will convert revolvers to DAO by removing the horn of the hammer with an angle grinder, such as in the case of the old Fitz Special revolvers.
  • Semi-auto double action/single action: DA/SA semi-autos work different than revolvers. The first trigger pull is a long and heavy double action shot, because it sets the hammer and trips the sear. Subsequent shots are single action with a lighter weight and shorter pull, as the cycling of the slide cocks the hammer. Some DA/SA autos include a decocking lever (which safely lowers the hammer) or a decocking safety that returns the pistol to double-action mode and blocks the firing mechanism.
  • Striker fired: These have no exposed hammer on the slide's rear. Striker-fired handgun models (like the ever-popular Glock, but there are others like the Smith & Wesson M&P) have a long but relatively light trigger pull that increases in weight as it travels the take up stage.
    The firing pin is initially half-cocked, which is brought to full-cock just before the trigger breaks and releases the sear. The sear trips the firing pin, which has a striker rod at the terminus of the firing pin. The striker rod contacts the primer. During recoil, the slide half-cocks the pistol again in most striker-designs as the slide returns to battery. There are variations, but this is the basic method of striker-fired operation.
Read a more in-depth examination of hammer vs. striker fired pistols Bigfoot Gun Belts previously published: Is Striker-Fired or Hammer Fired Better for Concealed Carry?

Note that these aren't the only types. Test out different types on the range, do more research and gain familiarity before the unfortunate day when you have to rely on your right to bear arms for self-defense.

Everyone has opinions about the different types of actions and their perceived benefits. Choose the type of action that suits your needs best.

There is no perfect firearm (despite contrary opinions on that). There are only handguns that function. That being said, a perfect firearm is one that serves all the needs of the individual carrier and functions in a way that benefits their intended use.

Stages Of Trigger Pull

trigger pull stages

Though there are different types of trigger mechanism, the trigger pull itself has several stages. Regardless of the trigger mechanism, the stages of trigger pull are the same though the dynamics of the trigger pull will be different with each different mechanism. They are:

Take-up or pre-tensioning: the initial stage of the pull. Take-up is usually short and easy, as this stage of the trigger pull goes from a slack trigger to the initial loading of tension. Striker triggers usually have a longer take-up stage, and are known for a good amount of "creep," the phenomenon where the trigger travels a great deal before tension applies.

Travel: at this point, the slack has been taken up and the trigger has begun to travel backward. The full weight of the trigger will be felt at this point; it will be like a "wall" of tension has suddenly entered the trigger pull.

The break: at this stage, the sear trips and the pistol fires. All tension will be relieved.

Overtravel: the trigger travels a short distance after the break, after which return travel begins if not held completely down.

Trigger reset: the reset is the point in return travel where the trigger re-engages the sear. The pistol can be fired again if need be; many shooters will "ride the reset" in rapid fire once they've become attuned to the reset point in the trigger stroke. Some pistols have an audible, tactile reset that is very easy to detect. Others are almost imperceptible.

Return: the trigger returns to its resting position.

Though these are the stages of trigger travel, there are actual "two stage" triggers, with two literal stages in the trigger pull. The first stage sets the trigger, usually with a lighter take-up and a breaking weight only a touch heavier.

However, two-stage triggers are only really found on rifles; except for totally custom pistols, handguns (and shotguns) use a single-stage trigger. The difference between the two is a two-stage trigger can be set and left in the second stage; a single-stage trigger has to be pulled all the way or not at all.

To get a better feel for a trigger, you should spend some time dry firing the gun. In fact, it will do your shooting a lot of good.

Why Does Knowing The Trigger Action Matter?

trigger action knowledge

That question will frustrate veteran gun owners, but for folks who are new to handguns in general, trigger actions might be an afterthought when strolling into a gun shop for the first time.

There are benefits to each type of trigger mechanism, as well as drawbacks. Understanding each and researching others will help cater a firearm to the individual's preferences. Some people will find that one type of trigger mechanism may suit them better than another.

Hands come in different sizes and strengths. Some may find the longer, harder trigger pull of a double-action revolver or double-action semi-auto all but untenable. Shooters without sufficient trigger time may also find the double-action first shot of a DA/SA semi-auto to hinder accuracy, as compensating for the trigger may pull shots.

Additionally, many find that DAO revolvers and striker-fired pistols are advantageous for concealed carry, as the lack of an external hammer aids in drawing from cover.

But, single action/double action handguns are useful for everyday carry due to the longer initial trigger pull, which when stored may ward against negligent discharge. Multiple polymer striker-fired pistols come equipped only with a trigger safety, which has resulted in a number of negligent discharges.

Single-action pistols either require to be cocked as they are drawn or - in the case of semi-auto single action pistols - carried with a manual safety engaged (aka "cocked and locked") which requires training to make second nature, which it needs to be for a concealed carry gun. However, it isn't as difficult as some people make it out to be.

At the end of the day, does any of this matter? Yes. All of it does, but how much it matters to YOU is going to come down to an economy of scale. You'll have to try each of them out to get a feel for each one. You'll likely figure out which you favor.

But, there is at least one universal constant in handgun ownership: make sure that you train with the firearm you have.

This is a brief introduction to this topic. Let others know more specifics in the comments, or check out these blogs we've published on trigger actions.

Jake Smith  

About The Author

Jake Smith (@notjakesmith) is a copywriter and photographer based in the Pacific Northwest who enjoys shooting pictures and ammunition outdoors.

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