Stan I don't think we are disagreeing on why SxSs need convergence but I think this might settle whether we do or not.
Suppose my shooting student Joe Wood and I are out dove hunting. A dove flies up and lands on the barbwire fence, to the right of a decoy. (That is Joe's favorite shot by the way). This sitting dove is 35 yards away. And suppose Joe is shooting his two-frame Parker 12 with 32" barrels and extra full chokes. Now, for the sake of argument, suppose the tubes are perfectly straight as advocated by you and Miller. Joe takes careful aim at the dove, setting it right on top of the bead. The rib points exactly at the dove. Since the barrels converge the right barrel is pointing to the left of the dove. Joe pulls the right trigger, the firing pin hits the primer, the powder ignites, the shot starts down the barrel. Because of the recoil the gun and thus the right barrel rotate to the right, approximately around the buttplate. As the barrel is rotating to the right the shot charge is coming down the barrel. Just as the shot charge exits the muzzle it is headed parallel and a little to the right of the line the rib was on before Joe pulled the trigger. The shot, except for vertical curve, goes straight to the dove and it falls to the ground dead. Joe yells "YEEEE-HAAAAW" and does his victory dance.
Now, same scenario, except Joe pulls the trigger and the gun fails to fire. He pulls the left trigger and it also fails to fire. Joe opens the gun and discovers he forgot to put the hammers back in it when he worked on it the night before. I hand Joe my two-frame Parker 12 gauge with 26" tightly choked barrels. And for the sake of argument lets say it had straight tubes as you and Miller contend. Joe aims carefully at the dove on the barbwire. The rib is pointed exactly at the dove. Because of convergence the right barrel is pointed to the left of the dove. It is pointed even further to the left than the 32" barrels because the 26" barrels have a higher rate of convergence. Joe pulls the right trigger. The recoil causes the gun and thus the barrels to rotate to the right as the shot charge goes down the barrel. But since the convergence rate of the 26" barrels is higher than the 32" barrels when the shot charge leaves the muzzle its direction, instead of parallel to the original line of the rib (before the Joe pulled the trigger), is at an angle to the original ribline. In a few yards the shot charges crosses the original rib line and goes to the left of the sitting dove, hitting the decoy and knocking it down from the wire. Joe yells "YEEEE-HAAAAW" and does his victory dance. The dove looks around, shakes its tail, and flies off.
Last edited by AmarilloMike; 05/10/14 09:21 PM.
