The designs are largely based on the Browning action found in the M1911 pistol, but with minor variations, generally related to the safety mechanism and the barrel-camblock interface.

Reviews have considered them rugged, reliable, and strong, though this strength comes at the price of bulk and a blocky appearance.

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.

[2][3] The pistols make extensive use of investment-cast parts and proprietary Ruger alloys.

It was, however, able to compete in the later XM10 trials in 1988, for which Ruger supplied 30 P85s to the Aberdeen Proving Ground in Maryland.

Despite performing well, the Beretta M9, which had succeeded at winning the previous two competitions, won once again and was awarded the contract.

The P85 found popularity on the civilian and law enforcement markets but many were recalled after one incident with the firing pin, resulting in a discharge.

The P85 was recalled, and a new safety was installed that prevented contact between firing pin and hammer during a decocking operation.

By then the P89 was in production (having been introduced the previous year), which is essentially just a re-branded P85 MK II.

In 1992, Ruger produced a limited-run P89X convertible model, which came with a second barrel and recoil spring assembly that allowed conversion between 9 mm and .30 Luger calibers.

The P90 is a scaled-up version of the P89 chambered in .45 ACP with an investment cast aluminum alloy frame.

It was introduced in 1991 as the company's first attempt at a .45 ACP pistol, and was in direct competition with SIG Sauer's P220, Smith & Wesson's 4500 series, and to a lesser extent Glock's G21 that came out the same year.

A larger number of P93s than other variants were also double action-only without an external safety, due to its intended concealed carry market.

Introduced in 1996, the P95 incorporated a number of changes from earlier P-series pistols, including a shorter 3.9-inch (99.1 mm) barrel like the P93.

The first P95s came with a glossy black polymer frame with a hooked trigger guard and lacking an accessory rail and grip texture.

Later model P95s featured a matte polymer frame with enhanced grip texturing, an accessory rail and a round trigger guard.

The P345 features a radically different design (as it was intended to usher in Ruger's new pistol designs) 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 P95 and P97) and low-profile safety levers.

It was designed to be legal for sale in states that require elaborate safety measures.