The lower butt moldings will end at various places depending upon region and builder. Some - primarily earlier stepped stocks - will end at the rear guard return. Some will run up into the trigger plate, typically on straighter stocks or stocks with no step. Then you have the Lehigh and eastern Berks pieces that often terminate somewhere in the middle of the trigger guard grip rail, which seems odd but has somewhat of a charm and grows on you. So the bottom line is to determine what region and/or particular maker you may be emulating, and go from there.
