Joe, I wonder if it were possible for any one of us to measure shot strings out of several different guns, of several different gauges, using the same (let's say 1 oz.) payload, if there would be individual small bore guns that might have as short, or shorter, shoestrings because of the way the individual gun is bored, choked, the forcing cone in it, bore diameter, etc.
SRH
Much as we might wish it to be so Stan, it's highly unlikely.
The shot charge from a cylinder bore gun leaves the barrel with a longer string the smaller the bore for a given shot weight. Nothing can change that.
Choke, any choke at all, induces a speed differential between the leading and trailing pellets as shown by photography.
There is simply no mechanism at play that can possibly shorten the shot string once it's free of the barrel.
Does it matter much? Only on fast and long crossing targets.
Shoot what you like, but don't expect your favorite rig to defy physics. The ideal shotgun would have a bore the size of one layer of shot. The shot string would be zero, all of it arriving at the plane of the target at the same time.
