Originally Posted by Wingbone

If your barrel was rigidly fixed to the receiver, there would be no problem. In a takedown shotgun, however, the barrel can slightly change it's aspect to the receiver every time you take it apart to clean it and retighten the magazine cap up reassembly. Small changes in aspect will really affect the POI. It will help to not take down your gun to clean it after you've sighted in. Or at least pay attention to the number of turns applied to the magazine cap when you re-tighten it.