Marc, the gap is there to allow the action to flex upon firing and not cause undue stress to the barrels and lockup. If there was no gap and everything locked tightly the forces released in firing would soon jerk the action apart. So, in a way, the gap is somewhat a shock absorber. Unfortunately many guns that are put back on face today do not leave the gap and the lifespan of the job is much shorter than what it originally was. Clear as mud?

John McCain is my war hero.