With no intent to insult, shoot the pistol from a benchrest BEFORE you file or bend anything. If it is off on windage, send the pistol along with the targets back to Ruger, they will correct the windage for you. SOME other manufacturers will do the same, if the maker of your pistol will not do it for you, any reputable 'smith can do it for you at a minimal cost. If you are going to do it anyway, it's best to turn the barrel, It is my understanding that cast frames, ie Ruger, are best done with a tool made specfically for this puropse instead of a block through the frame. I heard this from a fairly well known gunsmith that worked for AWA for what ever you might value his advice.
Butler Ford