[JayBell]

the issue with longer/shorter barrel lengths lies in the various definitions of "firearm" that PA uses.

the firearm definition for CCW use specifies items that are legal to be carried concealed on the person.
a big shotgun and rifle are not concealable, thats why the firearm definitions regarding barrel length are there, a SBR, SBS are concealable.
Also, when transferring NFA firearms with sub title 1 barrel lengths, the pistol form must be used along with 4473.
say, a 20" barrel M16 is ok for PICs on the 4473 after transfer, but a 11.5" barrel one would have to go on the PA state form also.
its all related to barrel length, not necessarily the function of same.

Also, never lie to a police officer.
the answer that nothing illegal is in my vehicle is an evasion, but is not a lie.
I don't choose to participate in fishing trips by the law.
If I am asked a SPECIFIC question, such as "Are you armed, or do you have a weapon on you?" I reply truthfully "I have a permit to carry a weapon, and i have a weapon on my left/right/backwhatever side."
A professional LEO knows that permit holders are responsible, lawful, and an ally against crimes.

idiot power hungry cops and rookies are the ones I worry about, i dont want to get shot by an asshat with a gun cuz he feels like the man tonite.
Remain polite, no matter the provocation.
in extreme cases, keep the lawyer on speed dial, and phone him while the cop is ranting or whatever.