The question of whether a rifle should be regulated to shoot parallel or to one point bothers me. I had until recently always heard that they were regulated to shoot to a single point.

Now let's consider a hypethetical rifle that will make dime sized groups at 500 yards from each individual barrel.

When fired, the rifle jumps toward wich ever barrel is fired, so that the position of each the muzzles at bullet exit is further apart than the distance beween muzzles when at rest. Lets say this distance is 1.5 inches. If regulated in parallel, then both barrels will be 1.5 inches apart at all ranges. But if regulated to one point at 100 yards, the two groups will converge going from muzzle to 100 yards. from 100 yards to 200 yards they will diverge back to the muzzle distance of 1.5 inches At 300 yards they will be 3 inches apart. Now 3 inches at 300 yards is quite good hunting accuracy and treading on the edge of bench rest accuracy. So I am not convinced that there is a practical difference in use. It does seem to me that regulating to a single point would be simpler. Also keep in mind, the two barrels will not produce the same velocity so there will be a difference in drop at extreme ranges.