Good morning Stan.
Bore is .404
Left barrel is .007 constriction. Factory Mod as marked.
Right barrel is/was .013.

Not even Briley had the tool to cut a .404 bore.
R&D Custom threaded the right barrel for a Truelock choke.
Constriction in the right barrel now measures .007

[Linked Image from i.imgur.com]

Trigger pull slightly less than 4lb in the right, just a scosh more in the left.