The Ruger P-series pistols started with the P85. All P-series handguns were designed with the one goal - to produce high quality, reliable and affordable service and personal protection pistols.
On the inside, all the P pistols are recoil operated locking-breech automatic pistols. They use SIG-Sauer locking, which is when one large barrel lug meshes with a large ejection port on the slide. All P-series are Browning-style tilting barrel pistols. Models prior to the P95 use the Colt 1911 style link system, while P95 and P97 use a newer linkless system.
The P85 was designed in 1985, and was introduced to the market in 1987. It had some drawbacks, non-ergonomic controls and sub-par accuracy. The original P85 had only one trigger variant, double action with a safety that also worked as a decocker. This safety blocked the firing pin and lowered the hammer. Ruger now offers three available versions of trigger- Double Action, Double action with decocker only, and Double Action Only (DAO). An automatic internal firing pin safety is standard in all variations.
The P89-P94 frames are made from hard coated A356T6 aluminum alloy, the slides from 400-series stainless-steel, or chromemoly in blued models. P95 and P97 frames are made from polymer much like that of a Glock. Slides are made from high strength steel or from stainless steel as an option. Grips on pre-P95 models are made from polymer, and are built into the frame on the P95 and P97.
The sights are dovetailed for a quick draw, and are marked with white dots for fast target acquisition.
All P-series pistols are extremely sturdy and reliable, able to continuously fire high-pressure +P loads without any damage to parts. They are often referred to as "built like tanks", and when speaking about P89s and P90s - "the bricks with the triggers", because of a somewhat cumbersome external appearance. This was improved with the P93 and later pistols that featured more streamlined slides and frames.
An important feature for those with little gunsmithing experience is that all P-Series pistols are easily field stripped without tools.
A large ejection port on the slide allows the user to load cartridges one at a time in the event of magazine malfunction and also allows misfires to be cleared quickly. All come standard with a hard plastic case, brass lock with keys, spare magazine, and loading tool and manual. All models have small compensating ports drilled through the slide to improve the accuracy of follow up shots.
Manual Safety
These models incorporate a manual ambidextrous safety lever that, when used, pushes the firing pin forward into the slide, out of reach of the hammer. At the same time, the firing pin is secured, preventing forward movement. The gun cannot be shot until the safety lever is moved back to fire.
Decocker-Only
In Decocker-Only models, the hammer is decocked by depressing either of the ambidextrous decocking levers. When released, the levers spring back to the "fire" position. After decocking, the gun can be fired by a double-action pull of the trigger without further manipulation of the decocking lever. Many law enforcement agencies prefer this because it allows the weapon to be carried loaded but safe.
Double-Action-Only
Double-Action-Only models have no external safety, or decocking lever. They are similar in operation to a revolver, the firing pin is blocked from forward movement by an internal safety until the trigger is pulled. Operation is "double action only" for each shot. All DAO models come with a spurless hammer.
Coming later:
Node them please!
P89
P90
P93
P94
P95
P97
To offer my opinion on these handguns, all are reliable and well built, but for home defense or concealed carry, I opt for the P95. 9mm is a very popular cartridge, and the polymer frame makes the pistol light enough to wear daily. At half the price of a Glock or Beretta, Ruger has made a durable, accurate and light pistol that can be had for about $350.
In response to Rancid Pickle's node, I would like to add that the feeding issue was likely the result of the old 1911 style linked action. The newer linkless style is a near copy of Sig-Sauer's, and should proove to be as reliable as the famed Sig P220, the choice of special ops teams as well as the Navy Seals.