The slide stop on the original P85 was positioned below the bottom edge of the slide, and its wide, grooved thumb-engagement surface extended backward above approximately a third of the depth of left-side grip panel. The current slide stop sits notably higher on the gun with its thumb-engagement surface well above the top of the frame and angled inward over the frame’s beefy top shoulder, almost even with the bottom of the manual safety lever. And it extends about a quarter-inch less far back. The reasons for the design change were to streamline the gun’s profile and to reduce the amount of the slide stop’s outward protrusion, which was found to cause a bit of drag and resistance with some holster designs.
Barrel manufacturing design has also improved. Original P85 barrels were of two-piece construction with the barrel and the square breechblock pressed together and then welded. It was a time-consuming and expensive manufacturing process. Current barrels are cast one-piece with broached bores.
Also notably better than the original is current P-Series trigger pull quality due to internal changes in the sear/trigger engagements linkages and parts configuration. The sear pivot pin has been reduced in size from original models, and the trigger bar has been thickened and the hammer-spring seat pin has been enlarged. The new mechanism also involves a bearing and slave pin to hold the sear-blocker lever spring assembly together as a coherent unit. The overall result is a distinct smoothing of the trigger pull due to the bearing’s considerable reduction of friction in the sear assembly’s operation.
Safety function is always critical to all Ruger designs. A substantial improvement was introduced with the P89 group of guns that modified the position of the firing pin when locked in the “Safe” position. The change eliminated the possibility of any transfer of energy from the hammer to the firing pin during the decocking procedure, which ensures the safety of the pistol even in the rare event of a broken firing pin. This modification was undertaken after it was discovered that with the original P85 safety design a broken firing pin could possibly become positioned such that depressing the safety/decock lever might strike the broken end of the pin in such a way as to cause the gun to fire. The new design eliminates this possibility, and Ruger has widely advertised an offer to provide a free factory safety modification to the owner of any P85 pistol made between 1987 and 1990 who wants the same new feature incorporated into his gun. If you have a Ruger P85 from those years and have not done it already, I recommend you call Ruger at 800-424-1886 and make arrangements to return your gun, even though no injuries have resulted from an older broken firing pin.
