Απολύτως αποδεδειγμένο. "Shotgunning, the Art and the Science" του Bob Brister.
One of the main principals that Brister found was that the more open the choke, the longer the down range shot string was. This was particularly true with soft lead shot, though the difference in shot string length between open and tight chokes diminished radically when hard shot was used, to the point where it was hardly noticeable with steel shot. Now, Brister's published findings could be the result of bad interpretation of data, except that he uses some very sound engineering principals to explain why. And, every other ballistician I have ever studied has come to the same conclusions. Roster, Blakeley, Brinnell, Tim Woodhouse and many others have long subscribed to the tighter choke/shorter shot string theory.