The PC is an off production line, semi-custom manufacturing arm of S&W. Exclusive models with enhancements. Here is how S&W defines the PC:
"ABOUT PERFORMANCE CENTER
From hand cutting to fine tuning for precision, Performance Center firearms are top performers. Products from the Performance Center are the ultimate expression of old-world craftsmanship blended with modern technology.
Feature-rich and enhanced for better performance, our firearms maintain production line integrity. Whether you're shooting a pistol, revolver, or rifle, you can be sure your Performance Center gun is made with a close attention to detail for your best shot yet."
I am not aware of a PC version of a model 25-5. If there is one somebody will chime in. PC guns usually have the PC logo roll-marked on the L/S of the frame.
Adios,
Pizza Bob