That’s right Edgar and when machining the hook, no matter how little, you’re drawing the barrels back into the frame a bit tighter than they were. Then the rearmost surface of the doll’s head comes into contact with the frame and it must be filed to fit… and the amount of metal that is filed off is equal to the width of the gap that remains at the shoulders of the doll’s head. It’s simple physics… “equal and opposite”.





.

If the wear is on the hinge pin and it is decided to add material to the barrel lug to correct the problem then by necessity everything including the dolls head has to back to the breech. When fitting the lug you have to remove the same amount of material that the barrels were off face in order for the gun to close.

Remington era
 

Remington era looks a little different on this 241XXX vent rib gun.
X
X

Yes Stan there is a more expensive way of avoiding the gap and that would have been to remove the doll’s head rib extension and file metal from the front of it so that when it is aoldered back in place there would be no gaps as shown in a few of preceding pictures… but that is very labor intensive and expensive.

Another cheaper way would be to add metal by welding to the areas displaying the gaps and finish filing it to fit correctly.





.

Tig welding the dolls head can be accomplished but it is very time consuming thus it is expensive. Vulcan barrels fitted to early hammerless damascus guns almost always result in a poor fit.

:banghead: It boggles my mind how you can think this.

When a gun goes off face, it is NOT because material has worn at the back end of the barrels. It is because the hinge pin and hook clearance has increased with repeated wear and, to a lessor degree, the opening and closing of the gun. This gap increase allows the barrels to move forward, away from the breech face. Correcting that wear, by either adding material to the hook, or installing an oversized joint roll, simply puts the barrels back against the breech face, Precisely where they were when the gun was built.
There is never any need to 'file' the back of the dolls head. It's simply being put back to where it was when the gun was built. Not to mention, you can't file the back of the dolls head, on an ejector gun, because of the stop plate and screw. Another thing you're forgetting, is the rear lug of the barrels. The back surface of the rear lug is within .001" of the frame, below the bolt.

I see the world is back in equilibrium!:rotf:

If barrels are “set back” then that area of the rib extension will open up. It is just a fact of the matter. And most would not want to mess with the super delicate work of welding a rib extension in that area and refitting it and potentially having a real mess on their hands.

In an ideal world when tightening a gun up, one would make up for exactly the worn material. But in reality, it ends up being adding more material than needed and then fitting accordingly. Once the hook is good, the breech of the barrels is fitted, and then the extension ends up with that gap.


One may wonder how the new guns are so precisely fitted. Yhe barrels were first fitted to the frame with no rib extension on them. Then the rib was cut back and the fitting of the extension was a separate operation after the fact. So, no they were not having to fit the hook, breech face and extension at the same time like we have to deal with today when putting back on face.

Edgar and Dean this has had me in a state of confusion all day. Edgar you finally brought the light to my dull mind. If it were necessary to remove metal from the rear of the doll's head then it follows that the breech face of the barrel's were too far back and metal would have to be removed there or the breech face.
I think the reason for these gaps eludes us.

Thanks Brian.





.