Difference Between Single and Double Action (With Table)

In the case of any firearm, an action is a functional mechanism that enables the ammunition cartridge to work. Furthermore, this type of mechanism has been categorized in numerous ways, such as single action vs. double action, break action vs. bolt action, and many more. To put it in simple words, the process of breech loading a firearm to fire the ammunition is called an action. 

Single Action vs Double Action 

The difference between Single Action and Double Action is that after pulling the trigger, the single action takes only one step to ignite the firing process. However, on the other hand, the double-action performs two functions that are cocking the hammer and then firing the gun.  

Single action is the rudimentary and simplest step of any type of trigger. The terminology single-action denotes the only function of the trigger, which is to release the hammer. Moreover, single-action is mostly attached to single-shot and repeating long arms like rifles, shotguns, and machine guns.  

On the other side of the page, a Double action is also a type of rudimentary mechanism but performs two steps to fire. The trigger of double action is the combination of double functions, which encloses both the cocking and releasing the hammer. Besides, this type of action is a prerequisite of a trigger-pulling design. 

Comparison Table Between Single and Double Action

Parameters of ComparisonSingle ActionDouble Action
MeaningA single action is a basic type of squeeze trigger, which releases the hammer of the firearm that results from each separate shot.Double Action is a type of trigger, which requires two functions- firstly, to cock and strike the firearm for a shot.
EtymologyThe incipient of single-action usage in firearms came in 1872, which was made by William Mason and Charles Brinckerhoff Richards’s Colt’s Manufacturing Company. Double Action was invented by Robert Adams in 1851.
MechanismAs, single-action operates in single shots, which functions when the trigger is pulled to release the hammer to be cocked subsequently by the fire of cartridges in the chamber. The mechanism of a double-action works in two functions- one is to cock the hammer and release it in a single row to get the fire shot.
WeighSingle Action firearms weigh around 4-5 pounds.Double Action weighs heavy, which is estimated at around 4-10 pounds. 
ExampleColt Single Action was an example of Single action, which was created by the same name- Colt’s manufacturing company.Taurus PT 92 is a double action that is largely sold in the market.

What is Single Action? 

A Single Action trigger is the most rudimentary type of trigger that has only one function to perform- to release the hammer or striker of the firearm. Following the release of the hammer, it will be cocked by separate shots. Before the invention of double action, most triggers were single actions. Eventually, the term Single Action has been in use since the mid 19th century. 

These triggers usually don’t require a person to physically operate the trigger mechanism but to just squeeze the trigger. Single action is often used in revolver triggers for firing. Originally, the usage of Single Action in firearms was manufactured by Colt’s Manufacturing Company in 1872 by William Mason and Charles Brinckerhoff Richards. 

The single-action process takes place when the trigger is pulled to release the hammer, followed by the firing of cartridges in the chamber. These triggers are manually operated prior to each shot. Single action is very light weapons weighing around 4-5 pounds. For instance, 241 Pistol Single Shot 410 inch Caliber This Belgian is a single action weapon. 

What is Double Action? 

On the other hand, double action is a type of firearm trigger that involves two functions, first to cock, and the second step is to release the hammer or striker in order to successfully fire. It neither has an internal sear mechanism to hold the hammer in position nor the whole hammer shrouded with thumb spur design in its weapons. 

Double action requires the design of trigger pulling, where everything remains in position until the trigger is pulled. Robert Adams is the patent of the first double-action revolver, who invented this type of trigger in 1851 to fire at a greater rate than any single action gun does. 

Speaking of its mechanism, a double-action revolver trigger cocks the hammer as well as releases it in a single go-to fire the shot constantly until the hammer is manually pulled back to its position. 

Unlike portable single-action guns, double-action weapons are quite long and heavy, weighing around 9-10 lbs. Taurus PT 92 is one of the widely renowned double-action guns. 

Main Differences Between Single and Double Action

  1. Single action is a basic trigger that requires one step to pull the shot, whereas Double action is a two function of a firearm to release a shot.
  2. Single action was introduced in 1872 by William Mason and Charles Brinckerhoff Richard. Meanwhile, Double action was introduced in 1851 by Robert Adams. 
  3. Single action operates by pulling the trigger, which releases the hammer to be cocked. Notwithstanding, Double action functions in two steps- First, to cock the hammer and release it in a single go to get a fire. 
  4. Single Action weighs 3-4 pounds, but Double action is heavy to carry and estimated to weigh around 4-10 pounds. 
  5. There are Colt, 241 Pistol, and 410-inch Caliber as examples of single-action firearms. On the contrary, Taurus PT 92 is famously known as a Double action firearm.


Single action and double action are ilks of trigger used in a firearm, Whereby single action functions only one step to release a shot, and that is to cock the hammer and release. Single action was invented by William Mason and Charles Brinckerhoff Richards from Colt’s manufacturing company in 1872. This kind of trigger is rudimentary as it involves a simple function to release the shot and is also convenient to carry as it weighs 3-4 pounds. Double actions are large and heavy to carry as well as to function because the weight of the firearm is evaluated around 4-10 pounds, and it requires two steps to release the shot- cock the hammer at the same time release the trigger in a single row. Double action was invented by Robert Adams in 1851. 


  1. https://www.sciencedirect.com/science/article/pii/S0196064401174548
  2. https://journals.lww.com/nsca-jscr/Abstract/1992/11000/Strength_and_Revolver_Marksmanship.8.aspx
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