Here is picture of the FBW falling block with my
700HE long case in it.This falling block is 1.5"
wide, with a 1.125" wide breach block.
The sides are .187" thick next to breach block.
This compares to about .165" say for a Browning
B-87, Win copy. The feed trough would work with
12ga size rim if some work was done on the top
of the hammer. This has a barrel thread length of
1.005", thread diameter of 1.125" for good
strength. Ed

[Linked Image]

Ed Hubel