Dolls Head/Rib Extension Fit?

[Dean Romig]

Originally Posted by edgarspencer

So, just to clarify, you don't really agree with me.
Putting a gun back on face involves correcting the fit of the hook and joint roll, which would not explain the gap between the frame recess and dolls head.
The fitting of the rib extension to the receiver, such as shown in the last photo, is done before it is soldered to the barrel. A barrel going off face is a change in the gap between the hook and joint roll, not the fit of the rib extension.

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”.





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[edgarspencer]

Originally Posted by Dean Romig

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. NO, you're not. Machining metal off the hook allows the barrel to go FORWARD. Then the rearmost surface of the doll’s head comes into contact with the frame and it must be filed to fit…The Barrels won't go any further back because they are up against the breech face. 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”.

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.