In PA there is a potential for liability if all the paperwork is not done. Under PA law private transfers of handguns must go through a FFL or the county sheriff. If you don't and the gun is used in a crime, you are liable and criminal. The only exception is transferrs between spouses or parent and child, but even then the transferee must be elegible to possess a handgun. This is how I, at 18, have come to own all of my handguns. My father buys them then gives them to me as a gift.
Longarms are a different story, you don't need to go through the sheriff or FFL, but, it is still illegal to provide an inelegible person with a firearm, so play it safe, or stick to family/friends/those who have been officially vouched for (CWP holders/active police)