You can mail (UPS or FedEx,
NOT USPS) a gun to yourself in PA, and back home again, without an FFL.
http://www.atf.gov/content/firearms-fre ... ed-persons" onclick="window.open(this.href);return false;
See question 9
Q: May a nonlicensee ship firearms interstate for his or her use in hunting or other lawful activity?
Yes. A person may ship a firearm to himself or herself in care of another person in the State where he or she intends to hunt or engage in any other lawful activity. The package should be addressed to the owner. Persons other than the owner should not open the package and take possession of the firearm.
Address the package to YOU, C/O (care of) your father at his home address and follow the UPS/FedEx rules for shipping firearms.
This assumes it is legal for you to possess the gun at your fathers home address.
This is my OPINION. IANAL.