Daryl you can see this much better if you go clear to the left on the picture of the top of the barrels. My 8 Bore has a dolls head and it fits tight all the way around. When a double rifle is rejoined the breach end of the barrels sometimes need to be filed to fit the breach again. This moves the dolls head back and creates a gap as the dolls head has to be filed to fit the action again. My experience is that the bigger the action that is re-color hardened the more chance of warping.