Clarifying Double Action Only (DAO)

by
posted on April 23, 2015
** When you buy products through the links on our site, we may earn a commission that supports NRA's mission to protect, preserve and defend the Second Amendment. **
wiley-clapp.jpg (1)

I recently had the pleasure of writing up the new SIG Sauer P320 for American Rifleman. Somehow or another, I left a number of readers a little confused about the pistol's trigger action, and we can't have that. So let's take a quick second look at the gun and see if we can get things straightened out. 320s are striker-fired pistols, a first for SIG Sauer. The striker is spring loaded and becomes fully cocked when the slide comes all the way to the rear, either manually or when the act of firing drives it back. To fire, the shooter presses the trigger, an act that clears safeties and releases the striker. This initial trigger pull does feel a great deal like several other guns (Glock, S&W M&P) that partially pre-cock the striker and are called DAOs (for double-action-only). undefined

But the correct technical definition of DAO is a system where trigger pressure performs the twin functions of cocking and firing. Since the P320 is already cocked, the trigger can only release the striker. It would have to be more like an SAO (single-action-only) trigger. It would probably be better to say that DA and SA are terms that define trigger action as it relates to the pistol's lockwork. Leave the clearing of passive safeties out of the equation, even though they make some of these trigger systems feel very DA-like. Somehow, the term DAO has come to be associated with greater safety in handling, so it is unlikely that the makers will cease using it on guns that are clearly fully cocked. undefined

It is also interesting to note that proper use of the reset point in the trigger can be so very useful. For the first shot in a series, the shooter has to sweep the trigger through a longer arc to get it in position to make that important release of the striker and fire. With practice, after firing the shot, he learns to allow the trigger to return only the short distance to where it resets the striker for firing. If he needs a second shot, he now moves the trigger back the same distance and it fires again. Like the old joke, repeat if necessary. There is usually a major difference in the length of trigger travel from all the way down to trigger travel from reset.

I hope this helps, but I am betting we haven't heard the end of the subject.

Latest

Savage 110 Trail Blazer rifle in 22 Creedmoor
Savage 110 Trail Blazer rifle in 22 Creedmoor

Review: Savage 110 Trail Blazer Rifle in 22 Creedmoor

Savage’s new 110 Trail Blazer rifle offers top-shelf performance at entry-level pricing.

I Carry: Springfield Armory Hellcat Pro 9 mm Pistol in a PHLster Holster

In this week's episode of "I Carry," we have a Springfield Armory Hellcat Pro 9 mm pistol with a Meprolight MPO Pro-S red-dot sight carried in a PHLster Skeleton kydex holster.

The Armed Citizen® Jan. 16, 2026

Read today's "The Armed Citizen" entry for real stories of law-abiding citizens, past and present, who used their firearms to save lives.

FN Releases New SCAR Rifles & QD Suppressors

FN made headlines when it announced it would discontinue its legacy SCAR rifle platform in 2025, but for 2026, the design is back and better than ever.

Review: KelTec SUB2000 GEN3 In 10 mm

At long last, KelTec has answered customer requests for a more potent version of their folding pistol-caliber carbine with its SUB2000 GEN3 chambered for the 10 mm Auto cartridge.

Lowering Decibels For Less: Lyman's New Sonicore Suppressor Lineup

As 2026 shapes up to be the "Year Of The Suppressor," firearm manufacturers are racing their new designs to market, and one of the most affordable options out of the gate is Lyman Products' Sonicore line of suppressors.

Interests



Get the best of American Rifleman delivered to your inbox.