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

Steiner Debuts 1
Steiner Debuts 1

Steiner Optics Debuts Overwatch Program to Support First Responders

With its new Overwatch Program, Steiner Optics now offers special pricing on select products for qualified military members, law-enforcement officers, first responders, corrections personnel and court officials.

Here for the Boom: How I Learned to Love the Big-Bores

A fear of recoil can turn into a longing for more kick. The author is proof of that.

Review: Taurus RPC

Taurus’s RPC brings a large-format pistol to the company’s lineup of revolvers and affordable semi-automatic pistols.

Old Meets New: The Springfield Armory Kuna Tri-Lug and .40 S&W Models

The iconic tri-lug muzzle of the H&K MP5 is now available on the Springfield Armory Kuna, allowing it to more closely match the original HS Produkt design while also allowing for easy mounting of suppressors.

The Armed Citizen® Sept. 7, 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.

Review: High Desert Cartridge Company Ammunition

Ammunition brands like High Desert Cartridge may not be as well-known as larger makers, but they can still offer excellent bang for your buck.

Interests



Get the best of American Rifleman delivered to your inbox.