Trigger Actions for Handguns: Common Types-Part1
Discussing handgun triggers and actions is never as simple as listing some universally accepted types and explaining their characteristics. I would prefer not to make this more complicated than it already is, particularly for people new to shooting, but there are a number of important factors to contemplate that could have dire consequences. When “action” is mentioned regarding handguns, it refers to the mechanical connection between the hammer and the trigger. Regardless of action, the basic function of a trigger is to release the striker or hammer. However, the trigger may cock the striker/hammer, rotate the revolver’s cylinder, deactivate passive safeties, or complete a number of other tasks. With some actions, squeezing the trigger could both cock and release the hammer, while only one action is performed with others. There are advantages and disadvantages to all actions. Many strong opinions exist regarding all actions, so it is important to research the subject yourself and make your own decision. What action do you prefer, and why?
Many shooters, when purchasing or using a handgun, don’t even consider trigger actions or types. They often don’t define what they want from the beginning when buying one. Consider the following: What are the usual types of triggers and which one best fits your needs? How does one type of trigger or action compare to another? What characteristics does each trigger type and action have? Will one trigger provide you with more accurate shooting than another? Will one trigger/action type give you faster firing in the event that you need to fend off multiple attackers? These questions are not intended to scare you, but there are a number of trigger/action factors at play when firing a handgun, and these factors have a direct effect upon shot placement, the amount of force required for the shot, follow-up shots, outcomes, and movement. One of the most important fundamentals of shooting is trigger control, if not THE most important. It’s important to understand how your handgun’s trigger and action function in order to correctly control it; practice and familiarity are crucial. Some shooters are even in disagreement about the trigger mechanisms, pros and cons, features, and benefits. The following is basic information about trigger actions, and is intended to be introductory for shooters who are new to shooting, as well as a review for experienced shooters. You should definitely be open to what others think about trigger types and what benefits they may offer, research them on your own, and come to your own conclusions. There are pros and cons to each type. This article is intended to provide understanding of the characteristics your current handgun provides, as well as to assist you when using it or buying a gun in the future.
Trigger mechanisms and actions on handguns come in five basic types. In this article, they will be referred to as types of triggers. The reason you should know what type of action your handgun has is because it will let you know whether the hammer must be cocked before the gun can first fire, whether a striker or firing pin operates, whether the firearm is only cocked by manipulating the trigger, how many actions must be performed for the weapon to fire, how much weight is required for the weapon to fire, whether you must cycle to slide to cock the gun, and many other things. Trigger type affects the shooter in many ways, not the least of which being follow-up shots, amount of movement, and how much force must be used to pull the trigger accurately and to defend yourself. Although the definitions of actions can be specified, there is disagreement and debate about the types of actions certain firearms have and how they operate. However, here are the five common trigger actions.
Common Trigger Action Types
Here are the five common trigger actions:
1) Single Action Only (SAO);
2) Double Action (DA);
3) Double Action Only (DAO);
4) Double Action/Single Action (DA/SA); and
5) Striker-Fired or Partially Cocked Striker (SF).
Single Action Only (SAO)
An SAO performs the single action of releasing the striker or hammer to fire the handgun when the trigger is pulled. Without the hammer being cocked first, an SAO handgun will not fire when the trigger is pulled. In most cases, the SAO has the simplest action with the lightest, smoothest, and shortest press. Because the press is consistent from shot to shot, minimal adjustments are needed for good accuracy. SAO pistols carry a major advantage in the fact that the firing mechanism, when cocked, can be released and fired with a short and soft press of the trigger, usually less than ¼” and about four pounds. Because less force is exerted in pulling the trigger, a more accurate shot is often performed. SAO pistols often use external safeties because the hammer will be cocked and the firearm ready to fire by chambering a round. SAOs are often carried “cocked and locked,” meaning that there is a round in the chamber and the safety is on. This carry technique requires proper training and practice, and shooters should be quite cautious when making this decision. The Colt 1911 Government Model, Browning P-35 Hi-Power, German P-08 Luger, Springfield 1911 EMP, Sig 238, Beretta Neos, Ruger Mark III, and Russian Tokarev TT33 are examples of SAO pistols. Although many early SAO firearms were revolvers (Colt Single-Action Army), there are semi-automatic pistols, like the Colt 1911, that must be cocked manually before the first round is fired, but are automatically cocked for successive shots, that are also SAO. Most shotguns and rifles use this trigger type. On an SAO pistol, you rack the slide to chamber the first round, and then the slide’s movement ejects the empty casing and chambers the next round automatically after firing. Although SAO pistols require the hammer or striker to be cocked prior to the first round being able to be fired, many also cock the hammer or slider as part of the loading process (inserting the magazine and moving the slide to chamber the first round will also cock the striker or hammer into a ready-to-fire position). After the first round has been fired, the recoil cocks the striker or hammer for each shot that follows it. Once the pistol has been cocked it can be fired once for each trigger pull until the magazine has been emptied.
An Ongoing Debate: It should be noted that many claim that striker-fired (SF) handguns are SAO because they fully cocked by manually cycling the slide or another operation. Others claim that SF guns are DAO. The fact is, there are different kinds of SF guns, and they are basically pseudo-DAO or pseudo-DAO. Some SF handguns, like the Springfield Armory XD, which doesn’t have a hammer and fires when you pull the trigger, are more SAO (some even debate this). Some handguns, like the Glock SF guns, are more like DAO with a partially cocked function that is pre-set. These are set apart from DAO firearms because, when the slide is cycled, it partially cocks the striker with a built-in, spring-loaded firing pin, and then, when the trigger is pulled, the striker bar finishes cocking and is released to strike the primer and ignite the cartridge and fire the weapon. The definition of SAO is that the trigger being pulled performs only one function–the release of the hammer or striker to make the gun fire. In a pure SF system, there is no external hammer, which means that there is no way to de-cock the gun. SFs are cocked when the slide is racked, and pressing the trigger is the typical method of de-cocking them. Some guns, like the S&W SW99 pistol, can also be considered pseudo DA-SA handguns. It is my belief that SF guns are neither SAO or DAO, but their own category. Some SF guns, like the Springfield XD-9 Mod 2, are single action, because racking the slide cocks the striker and the trigger releases it. Others are DAO because the trigger will cock and release the striker, regardless of whether the slide is racked. Most SF guns are a kind of single action and double action hybrid. In these hybrids, the slide might cock the striker, but the trigger completes the cocking action as well as releasing the striker (as in the Glock 17 and 19). Both slide and trigger actions are required for those guns to fire. The International Defensive Pistol Association (IDPA) has been debating the issue of SF guns for quite awhile. According to the 2015 IDPA Rule Book, Section 8.1.1.2, DA, DAO, and SF semi-automatic handguns compete in SSP, BUG, or CCP divisions while SAO handguns compete in a different division, like CDP or ESP, depending on the size of the gun and what cartridge is used. Prior to 2015, the IDPA categorized the Springfield XDm as SAO. The HKP7 family and Springfield XD line are two examples of single action SF guns.
Click next for Double Action triggers.
