Re: trueing question
like mentioned already, fully truing the action will include opening up the receiver threads to ensure they are centered/square to the bore, round and a true form. the factory barrel threads will no longer properly fit this new oversized receiver thread.
personally, i feel any <span style="font-style: italic">potential</span> gain from truing a receiver and setting back a factory barrel is no where near worth the time/cost involved. my advice is to shoot what you have now until you are ready to have an aftermarket barrel installed. at that time having the action trued up makes much more sense.