Why did they stop using the Double Action Pistol?

Summary

Massad Ayoob explains why traditional double-action/single-action (DA/SA) pistols were adopted, how their controls work, and why he believes they remain useful despite losing popularity to striker-fired pistols.

How the DA/SA system works

The first shot is fired with a long, heavier double-action trigger pull, which both cocks and releases the hammer. Firing that shot leaves the pistol in single-action mode, so subsequent shots have a shorter, lighter trigger pull.

Many models have a lever that safely lowers the hammer. Depending on the design, the lever may also function as a manual safety:

• A decocker-only design lowers the hammer and returns the pistol to its firing state.
• A safety/decocker design can leave the pistol on safe until the safety is disengaged.

Historical development

Ayoob traces the first widely popular DA/SA pistols to the Walther PP series, introduced near the end of the 1920s. The design helped make it possible to carry a pistol with a round chambered and fire the first shot with a revolver-like trigger pull.

The Walther PP influenced the later P38. Ayoob also describes Smith & Wesson’s Model 39, introduced in the mid-1950s, as the first American double-action pistol.

As police departments sought simpler controls, manufacturers offered models with decockers but no manual safety. Ayoob argues that some instructors inaccurately described safety/decocker levers as decockers only, despite manufacturers’ documentation. The video discusses examples from Beretta, Smith & Wesson, and SIG Sauer, including differences in the locations of their decocking controls.

Why agencies and shooters valued DA/SA

Ayoob recounts an explanation from FBI figure John Hall: the heavier first pull was intended to reduce unintended first shots, while the lighter subsequent pulls could help an officer fire more easily and controllably if a fight continued.

The system requires practice to manage the transition between the first, heavier pull and later, lighter pulls. Ayoob argues that shooters can learn this through regular practice.

He also points to the hammer as an added point of control while holstering. Keeping a thumb on it can help detect or resist movement if something presses the trigger, though Ayoob notes that this is not a substitute for safe holstering technique.

Safety cautions

Ayoob strongly advises using the pistol’s built-in decocking lever rather than manually pulling the trigger to lower the hammer over a live chamber. He warns that a finger can slip and fire the gun, and that some designs may not remain drop-safe if decocked manually.

He recounts a fatal accidental shooting involving a police officer who manually lowered the hammer of a SIG P220 before the holstered pistol fell.

For people unfamiliar with a decocker, Ayoob describes an unloaded “pencil test” to observe the mechanism’s movement. He presents this as a demonstration, not a replacement for the manufacturer’s instructions or qualified training.

Why striker-fired pistols became more common

Ayoob says striker-fired pistols are generally easier to train with because their trigger pull is consistent from shot to shot. Their polymer frames can also reduce manufacturing costs. He acknowledges that polymer-framed DA/SA pistols exist, so the frame material alone does not determine the action type.

DA/SA pistols have become less common among major manufacturers, but Ayoob concludes that their distinctive features still suit some shooters. He frames the choice as a matter of preference and application rather than declaring one system universally superior.

Speakers and sources featured

• Massad Ayoob — Presenter and principal speaker.
• John Hall — FBI figure quoted by Ayoob on the rationale for a heavier first trigger pull.
• Sources referenced by Ayoob — FBI training discussions, firearm manufacturers’ manuals and patent language, and Ayoob’s experience as an expert witness.