Although any type of firearms registration is expressly forbidden by PA law , the PA State Police have illegally maintained a so-called 'record of sale' database for handguns sold within the state , despite Supreme Court orders to dismantle it.
If you are stopped carrying a handgun and it is not in this registry , or registered to someone else , you just might have it confiscated till you can prove ownership , and even that might not be enough. This includes guns you may have inherited , or even bought legally while the resident of another state. The PSP even freely admit , this database is 'incomplete at best'.
It could lead to a long and expensive battle with you having to get a lawyer , and I think that's their agenda. Who's gonna pay thousands of dollars to get a gun worth a few hundred back.