The P series are short recoil–operated, locked breech semi-automatic pistols. They utilize a SIG P220 type locking system, and an M1911-style tilting barrel. The P series were made with a traditional double action/single action (DA/SA), or double action only (DAO) trigger mechanism.
The standard models have an ambidextrous manual safety/decocker located on the slide; when the safety lever is lowered to the safe position, the firing pin is cammed into the slide away from the hammer, the trigger is disconnected from the sear and the hammer is decocked. The decocker models have no manual safety; instead, when the lever is lowered it only cams the firing pin into the slide and drops the hammer. When the lever is released the firing pin springs back to the normal position. The DAO models have no manual safety or decocker. All models feature an automatic firing pin safety that blocks the firing pin unless the trigger is pulled fully rearward.
The pistols make extensive use of investment cast parts and proprietary Ruger alloys. Nearly all internal parts, including the barrel, are stainless steel; while the slide and ejector are carbon steel. The P85 through P944 use an investment cast aluminum frame, while the P95 and later models use a fiberglass-reinforced polyurethane frame.
The 9mm and .40 S&W versions use double-column box magazines; the 9mm has a 15 round capacity, and the .40 has a 10 round capacity. The .45 ACP versions use single-column magazines holding seven or eight rounds (depending on the model). All P series of the same caliber use a similar magazine design, but slight modifications have been made to at least the 9mm guns so that not all P series magazines will function in all P series frames. Ruger did not keep track of the magazine models so an older magazine may not secure in a newer frame. The Ruger Police Carbine also uses P series magazines. The P series pistols have an ambidextrous magazine release located behind the trigger guard, it can be pushed forward from either side to eject the magazine.
The early model P95's have fixed, three-dot sights; while newer P-95, P97 and P345 have three-dot sights adjustable for windage.
The Ruger P85 was the first model, chambered in 9mm and designed for Joint Service Small Arms Program as the new sidearm for the United States Military. Unfortunately, the design was not fully completed and the weapon was not fully designed until 1987, one year after the program was over and the Beretta M9 had already been selected as the new U.S. Army sidearm. It is thought that if it had been completed, it would have been a strong contender for the contest, since Ruger P-Series pistols have earned a reputation of reliability. It was only available with a DA/SA trigger, decocker, and a manual safety.
Early P85 pistols were recalled for a safety issue that resulted in one accidental discharge. If the firing pin broke in front of the firing pin block, applying the safety, which dropped the hammer, could transfer enough energy to the broken firing pin to cause a discharge. The P85 was recalled, and a new safety was installed that prevented contact between firing pin and hammer during a decocking operation. This modification was done free of charge. The P85 MKII was released with the safety fix, larger safety levers, improved accuracy, and the option of a stainless steel slide.
P85 production stopped in 1990, and the P85 MKII was discontinued in 1992, having been fully replaced by the improved P89.
The P89 is an upgraded P85 MKII that introduced a number of new features; including a DAO model.
In 1991, Ruger produced a limited run P89X convertible model, which came with a second barrel and recoil spring assembly that allowed conversion between 9mm and .30 Luger calibers. Ruger only made 5750 with both barrels.
The P89 was the most popular models. It was discontinued in late 2007.
The P90 is a scaled up P89 chambered in .45 ACP with an aluminum frame. The P90 is considered to have above average accuracy for its price. It was discontinued in 2010.
The Special Edition P90 was produced for Ruger by Davidson Firearms. The Davidson Special Edition P89/P90 gun featured a carbon steel slide, a matte gray receiver (i.e., the OEM one normally provided to the stainless steel guns), and stainless steel accents (trigger, safety levers), and, if it was a "TH" variant, the Hogue fingergroove rubber grips with the Ruger logo. The guns came in a Special Edition colored and labeled polymer box. While similarly priced to the stock P90, they only included one magazine.
The P91 is a version of the P89 chambered in .40 S&W. It was discontinued in 2004.
P93, P94 and P944Edit
The P93 is a compact 9mm model, with a shortened 4 in (100 mm) barrel and a streamlined slide and frame. The P94 is a mid-sized 9mm, with a 4.2 in (110 mm) barrel and the P93's streamlined styling. The P944 is similar externally to the P94 but chambered in .40 S&W. The P944 also introduced a camblock incorporated into the recoil spring guide rather than the M1911-style swinging link of previous version. This camblock was used on all P-series pistols designed afterward. The P93 was discontinued in 1994, and the P94 was discontinued in 2004. The P944 continued being produced until 2011.
Introduced in 1996, the P95 is essentially a 9mm Ruger P94 with a high-impact polymer frame. It incorporated a number of changes from earlier P-series pistols; including a shorter 3.9" barrel and a new frame replacing the aluminum frames that was made of high-strength fiberglass-reinforced polyurethane, based on Dow Chemical's "Isoplast". This reduced the weight of the pistol by 4 ounces (110 g) and reduced manufacturing costs. To this day, the P95's frame is often thought of as the strongest polymer handgun of all time. Unlike other polymer framed handguns on the market at the time of design, the P95 had no metal inserts in the frame. This was done both to compete with other polymer guns but also for ease of production. The high strength polymer allowed the slide to ride directly on the polymer frame rails which simplified manufacturing and further reduced production costs. Some were skeptical and concerned about this change but it quickly grew accepted that the frame was so durable that there never was a single reported malfunction with the rails. Few designs, if any, have attempted to do this since, likely because of the strength differences in polymers.
The P95PR was introduced in 2005, it incorporates a Picatinny rail into the frame and adds a new non-slip texturing in the polymer frame. This model replaced the original P95 in production.
In December 2004, Ruger was awarded a contract for 5,000 KP95D pistols by the U.S. Army Tank-automotive and Armaments Command, Rock Island Arsenal, Illinois.
The P95 was slowly phased out in recent years in favor of the newer SR series. Eventually, the P95 was quietly discontinued in October 2013 and removed from Ruger's website catalog, although there is still a page on the website for the P95.
The P97 is based on the P95, but chambered in .45 ACP. It was only available in decocker and DAO versions.
It featured an adjustable rear sight. The front sight is pinned in, and the rear held in by a set screw. The P97 is used by a number of police departments in the United States and elsewhere.
The P97 was discontinued in 2004.
The P345 was released in 2004, and incorporates an integrated keyed lock that locks the safety in the safe position, a loaded chamber indicator, and a magazine disconnect that blocks the firing pin when the magazine is removed. It also has many ergonomic improvements such as a new polymer frame design (narrower than the double column derived P90 and P97) and low profile safety levers. It does not feature an ambidextrous slide release or magazine release. Both controls are designed for a right-handed shooter. The model P345PR adds a Picatinny rail to the frame, for mounting lights and other accessories. It was designed to be legal for sale in states that require elaborate safety measures.
The P345 was also offered in a Distributor Exclusive edition by TALO Distributors, Inc. Only 500 units were produced between October and December 2007. This model featured a unique Serial number (1-500), 24k gold embellishments, and polished blued steel slide.
The P345 was discontinued in 2013 and replaced by the new SR45.