It would be interesting to see the laser bore siter put in the bores of a double rifle AFTER you regulated it properly and see the correlation of the lasers on the target.

If enough data was gathered in this way perhaps the laser bore siters could be used to provide a "starting point" for regulation that is much closer to the finished product than an amateur regulator might otherwise achieve.

Those craftsmen who regulate doubles regularly would have arrived at the starting point for regulation out of familiarity and have a "formula" that would produce a very close starting point in order to cut down on time at the shooting bench, cartridges and recoil.