Interesting theory . I believe its best to go with a straight bore . A problem can occur with long bores that sag with gravity causing the loss of contact with the bottom of the bore . Blowgun bores can be positional in the case of sagging . One should site down the inside of the bore from mouth end to muzzle end and rotate while viewing . Stop rotating when you have the best roundest opening view and mark the top of the barrel with a mark . The blow gun should now be shot with the mark facing up all the time . Now your holding the bore in its straightest position consistently while allowing the dart consistent bore contact .