If you are sure they aren't stripped, then when you do the final reassembly, use a drop of locktite blue on the threads. That way you can still get them out without a fire wrench if needed.
NRA Chief Range Safety Officer, Home Firearm Safety and Pistol Instructor
"There are three classes of people: those who see, those who see when they are shown, those who do not see."
Leonardo da Vinci