If one were to sleeve a SxS shotgun or to add rifled choke tubes to a shotgun, which would probably shoot better without regulation. A short (18")barreled version or a longer (26"-30") barreled version? I was thinking of getting a Baikal or Stoeger "coach gun" and screwing in some rifled choke tubes. Then I was going to make a collar that would slide over the protruding barrels, to cover the protrusion and also have a place to mount my sites. Would using a laser bore site, give some indication of the regulation, say at 50 yards or so?