Heres something that I thought the P97 fans would enjoy if you already don't know it. The P97 is unique from any of the other P-series pistols in the way they work.
Mechanically Novel
In terms of mechanical operation, the P97 barrel tilts to lock and unlock, Browning-style-as do all P-Series pistols. However, the P97 uses a camblock system to cause this motion instead of the Model 1911-type toggle link employed on metal-frame P-Series guns. During the firing cycle the P97 barrel is accelerated to a high speed as it moves back and down to unlock from the slide. Once it leaves contact with the slide, the barrel must be brought to a stop. As Ruger puts it in the P97 information release, "a novel system allows us to do so without impact damage to the polymer frame." Novel, indeed. "Unique" or "innovative" would be more how I would put it since the P97 system is different from any other metal or polymer .45 ACP pistol on the market.
The effect of barrel (and slide) impact has been a major engineering problem for polymer-frame autoloader designers since the moment Gaston Glock woke up from the middle of a good night's sleep with the original "plastic gun" idea in his head. Many different ideas have been tried and discarded, and a wide variety of different solutions are used by various manufacturers for their varying-caliber, current-production polymer-frame pistols. For high slide/barrel-acceleration loads like the .45 ACP, the most common systems involve either a separate metal recoil block or camblock of some sort set into the polymer frame or some type of cushioning system involving the recoil spring/guide rod assembly (or a combination of both). The P97 takes those concepts a step further.
On the P97 the linkless camming surfaces that guide and pull the unlocking barrel downward from the slide and absorb the impact of the barrel's rearward recoil acceleration are an integral part of the rear portion of the recoil spring guide rod itself. In fact, this part-which on any other autoloader would be called the guide rod-Ruger calls the camblock (there is no part actually called a guide rod anywhere in the P97). The thing looks like an ordinary full-length guide rod with a big, cam-ramped lug on the end, and it's a really neat design. The camblock is held in the frame by the crosspin of the slide stop. In firing, the barrel comes backward, is pulled away from the slide by the camming ramp, and is stopped by the recoil-spring-enclosed camblock with no direct impact against the frame at all. It's a slick idea, originally developed and patented by Ruger in slightly different form for the polymer-frame 9mm P95. And it works. Plus the P97 still disassembles and reassembles in a completely conventional manner, just like any other Ruger P-Series pistol.
