The latest offspring from the S&W-Walther alliance is a flawless performer, but it begs the question, "Just what is a DAO?"
By Frank W. James
The Smith & Wesson Model 990L is the latest variation of the Model SW99. Changes include a unique trigger mechanism and the elimination of the somewhat controversial decocker button on the top of the slide. Despite appearances to the contrary, the 990L isn't just another polymer-framed semiauto, and working with it led to an exercise in defining the characteristics and key elements of a modern double-action-only (DAO) pistol.
The Smith & Wesson Model 990L is a solid design and from indications experienced during our testing is an accurate and reliable semiauto pistol that will serve both law enforcement and civilian markets quite well.
Is it time for a new and different classification for such semiautos? For years we have classified semiautomatic pistols with terms originally used for revolvers. Single-action revolvers are simple machines to operate and understand. The shooter is required to cock the hammer prior to pulling the trigger and releasing the hammer, which is powered by the energy stored in the mainspring. That is pretty straightforward.
The traditional double-action revolver has always offered the option of single-action shooting by means of manually cocking the hammer before the trigger is pulled to fire a single round. Double-action shooting was originally called "trigger cocking" by the British, in reference to the Adams revolver, which used a mechanism patented in the U.K. by Frederick Edward Blackett Beaumont in 1853. The term meant that the trigger was used to cock the hammer and, in turn, store energy in the mainspring prior to its release, which occured as a result of the completed trigger pull.
The introduction of smokeless powder in the late 1800s gave designers and inventors the opportunity to create firearms that utilized the energy contained within the cartridge to operate the gun. All of these early-model semiautomatics required that the hammer or toggle be cocked because the gun at rest was simply inert. There was no kinetic energy stored within its springs or mechanism. These pistols were all defined as single-action semiautos, although few shooters used the term since these were the only semiauto designs in existence at the time.
The main advantage they offered the shooter was the "automatic" ability to load the chamber from a reservoir of ammunition after the round in the chamber had been fired. However, it is important to note that none of this action took place without the shooter first manually cocking the gun in some way to deposit the requisite amount of energy in the mainspring necessary to fire the first shot.
Interchangable front blade with single white dot. Windage adjustable rear with two white dots on either side of square-cut notch
CAPACITY:
10+1. Gun shipped with two 10-round magazines (12-round magazines available), three backstrap inserts, four front-sight inserts and a Master gun lock
PRICE:
$694
Then Alois Tomiska designed the first pistol with a trigger mechanism that would fit the definition of a double-action semiauto trigger pull with the 6.35mm Little Tom in 1908 and began producing it in 1913. But few people paid attention to it or to the Mannlicher Model 1894 that some commentators feel was the first DA semiauto pistol.
Things changed when Walther designed the Model PP, which was a blowback-operated pistol that fired the first shot with the completion of a long trigger pull. All that was required was a loaded chamber. So while many writers and experts claim that the PP was the world's first double-action/single-action semiauto pistol, the honor belongs to the Tomiska Little Tom or the 1894 Mannlicher.
The Walther PP was followed by the P-38, which was a recoil-operated, locked-breech DA pistol. Even though these guns were joined over the following decades by a wide number of products from other manufacturers around the world, the premise of operation followed that established with the double-action revolver. The premise was this: The energy of the mainspring that powered the hammer was empowered by the long, first-shot trigger pull of the mechanism. Prior to this first trigger pull, the mainspring and the hammer were at a position of rest.
All that changed when Glock's Safe Action was introduced. Some elements of its trigger mechanism are similar to those found on the long-forgotten Austrian Roth-Steyr (from the same era as the Little Tom and the Mannlicher 1894).
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