Stan: The purpose of arching those barrels back to back is so that the shot charge follows a line parallel to the line of the rib at the time the shot is fired. After the right barrel is fired the recoil causes the barrels to rotate to the right. The rate of this rotation is determined by the cartridge and the MOI of the gun. So the barrel is rotating to the right as the shot charge goes down the barrel. The intention is that when the shot charge comes out of the muzzle it is moving a line parallel to the rib at the time the shot was fired.
Mike, I understand all the physics behind why convergence is necessary. What you are saying, tho', is that the reason for convergence does not occur until after the shot charge leaves the barrel. Recoil is the reason. And that recoil begins to act on the gun, pulling it to one side or the other, BEFORE the shot charge leaves the barrel. If it didn't, convergence wouldn't be necessary. Recoil from firing the left barrel pulls the muzzles left, recoil from the right barrel pulls the barrels right. Now, stop and picture this a second. If the bores were parallel at, and near, the muzzle, as you say they are from bending the barrels, convergence of the axis of the two bores would not be necessary, because it would be counter-acted by the parallel section near the muzzles. I mean, why in the world would a barrel man put two barrels together with a converging angle, which is to counteract the recoil which pulls the gun to one side or the other, then make the bores parallel? That would be self defeating.
SRH
