[Linked Image from photos.smugmug.com]

The barrels are what Baker Gun & Forging called "Best London Damascus Twist", which was used on the Grade B hammerless

Did you use a rule to measure the chamber length? The chambers very likely started at 2 7/8", and if slightly over-size the rule would over estimate the length. It is critical that the end of chamber and forcing cone wall thicknesses be measured before using the gun.

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