Thursday, July 12, 2012

Just the Basics – the Double-Action Semi-Automatic Pistol



Another option shooters have with semi-automatic pistols is to purchase a version that has a Double Action trigger. As in a Double Action Revolver, the trigger performs two functions: First it cocks the hammer and second, it release the hammer to strike the firing pin.

In the case of a Double Action Semi-Automatic pistol, racking the slide will eject a cartridge or spent casing, strip a new round from the top of the Magazine and drive it into the chamber. However, it will NOT cock the hammer. That function is done by pressing the trigger to the rear.

Let’s take a walk through a Double Action Semi-Automatic Pistol.

The chassis, the primary component that holds all the parts together is the Frame.

The Barrel is the component that allows the bullet to exit the handgun after it is fired and adds a spin to the bullet to increase its accuracy.

The Muzzle is the region immediately at the end of the Barrel where the bullet exits.

The Front Sight, used in conjunction with the Rear Sight is used to acquire an accurate sight picture prior to engaging a threat.

The Hammer is manually cocked by pressing the trigger to the rear. The pressure is continued until the trigger “breaks” and the Hammer strikes the firing pin which, in turn, strikes the primer in the cartridge.

The Magazine contains the cartridges to be fired and feeds a new cartridge into chamber each time the weapon if fired – until the magazine is empty.

The Magazine Release is used to drop an empty magazine from the Magazine Well in order to make room for a replacement magazine that is fully loaded.

The Grip is the portion of the pistol that is actually “gripped” by the shooter. The Back Strap fits into the shooter’s palm and the Front Strap provides a purchase for the shooter’s fingers.

The Thumb Safety is a mechanical device that locks the slide in place and disables the firing pin.  It must be manually disengaged with the shooters thumb in order to prepare the weapon to fire.  (Remember, it is a MECHANICAL device and CAN fail.).

The Trigger is the component that is pressed to the rear that first cocks the internal Hammer and then releases it to strike the firing pin, firing the cartridge.  Many Double Action Semi-Automatic Pistols have a very stiff - and long – trigger pull. This, in many cases, takes the place of a manual or Thumb Safety.

The Trigger Guard provides protection against an accidental discharge from rubbing the Trigger against clothing or a holster.

The Semi-Automatic Pistol is loaded by inserting a loaded Magazine into the Magazine Well and seating it with a firm palm-slap to the bottom of the Magazine. The shooter than manually racks the Slide to the rear and releases it. This will strip a new cartridge out of the Magazine and load it into the chamber at the rear of the Barrel. From this point forward, each time the weapon is fired, part of the energy is captured to automatically force the slide to the rear, eject the spent cartridge out of the Ejection Port and to strip a new cartridge from the Magazine and load it into the chamber at the rear of the Barrel. This process will continue each time the Trigger is pressed until the Magazine is empty.

Unloading can be done by depressing the Magazine Release and capturing the Magazine as it falls from the Magazine Well. To display that the weapon is empty, rack the Slide to the rear ejecting any un-fired cartridge that may still be in the chamber out of the Ejection Port. Push the Slide Lock up into the notch on the Slide. This allows the shooter to easily verify the weapon is, indeed, empty.

This particular example of a Double Action Semi-Automatic Pistol is the Ruger LC-9. It is one of my favorite carry weapons. I completed the following video review shortly after I purchased the LC-9.



  1. You do such a great job of breaking things down and making them very easy to understand. Very good for the new shooter.

  2. AGirl : Thanks very much.

    NFO : Thank you sir, I appreciate it.

  3. An excellent primer on a firearm! (pun intended)

  4. This was helpful. I also really liked the picture with the parts of the gun labeled...question though-where is the Ejection Port?

  5. Hi Joey - glad it helped.

    As for the ejection port, well . . . Mmmmm . . . you caught me. I found that when I began to label the photo I had not taken a photo of the opposite side of the gun. And, I simply did not set up the lighting to take a second photo and just decided to move forward with the post. Hopefully folks will get the idea from the other two semi-automatic pistols that the ejection port is on the opposite side of the gun that is shown.

    Thanks for stopping by - and that you found value in the post!


  6. Never mind ...I saw the ejection port on the Safe Action Semi-Automatic picture.