You are picking up a pistol in your own state, and he is picking up a rifle, both are going through an FFL. That is all legal by federal law, and it is legal by Virginia law. The only question is if it's legal by Pennsylvania law if he is allowed to by a rifle in a other state. I have purchased a rifle at Cabelas in Pennsylvania, so I'd imagine the opposite is true.
As stated above check with the FFL
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Never initiate force against another. But should someone do violence to you, retaliate without hesitation, without reservation, without quarter, until you are sure that he will never wish to harm - or never be capable of harming - you or yours again.