Let's start our examination of the SR9 from the top and work our way down. While early Ruger pistols used investment castings to produce their slides, the SR9 is machined from solid stainless steel. This has enabled the company to reduce the width so that it is the narrowest of any of its contemporaries. The sights are mounted in dovetail cuts and prominent, easy to acquire, and fast to line up. The rear sight is adjustable for elevation so that the pistol can be zeroed in with a variety of loads.
When a round is chambered, a loaded chamber indicator rises above the slide, providing a visual and tactile indication of the pistol's condition while a massive extractor with a large claw ensures reliable functioning. Locking is via the barrel hood rising up into, and bearing against, the front of the ejection port. This holds the slide/barrel unit together until they recoil a short distance, whereupon the barrel is cammed down, allowing the slide to continue to the rear, extracting and ejecting the spent cartridge case. The captured recoil spring unit under the barrel then pulls the slide forward, feeding the next round from the magazine and pulling the slide/barrel unit into battery.
The frame is made of glass-filled polymer, and it is slimmer than the competition, with a grip frame angle that feels just like a 1911 pistol. The grip features impressed checkering on the side panels, front, and backstraps to improve recoil control. Not only does the SR9's frame feel like a 1911, but removing a single pin allows the shooter to reverse the backstrap, giving a choice of flat or arched styles (personally I prefer the latter). As is common on service-type pistols today, a Picatinny frame rail allows mounting of tactical lights and/or laser sights.
The slide reciprocates on rails on the steel camblock—which also acts to cam the barrel down during movement—and steel inserts at the rear of the frame. This camblock also serves to disperse recoil pulse through the frame, lessening felt recoil. The SR9 is a striker-fired pistol and as the slide goes forward into battery, the striker is held in a partially cocked position. Pulling the double-action trigger draws the striker back completely, disabling the firing pin safety plunger and then tripping the sear to release the striker to fire the pistol. The SR9 also features a magazine disconnect safety.
In addition to its passive safety devices, the SR9 has ambidextrous thumb safeties, something which I feel is sorely lacking on many of today's striker-fired service pistols. While they have a very flat profile, and are positioned close against the frame to reduce the chance of them hanging up, they are serrated for positive manipulation. The SR9's southpaw bonafides are further enhanced by its ambidextrous magazine release buttons.