Would it be legal for a Maryland resident to open carry in Virginia?

MD law allows you to transport to and from an organized shoot event or a range. It does not restrict you to MD so even if you are pulled over either going or coming in MD you are OK under MD 4-203. I guess you might be asked to prove that you were going to or coming from an event or organized shoot ,however the AG opinion should cover that as well. I think I'm prepared to deal with either situation. I keep a copy of FOPA, and the AG opinions in my gun safe in my Jeep. Hopefully that will suffice

The AG has also issued an opinion that loaded magazines are ok in MD as long as they are not inserted in the firearm. I keep a copy of that in my vehicle gun safe as well.