The A.H. Fox Co., as did the other turn-of-the-century double gun makers told us exactly the loads recommended for their guns; this is from the 1914 Fox catalog courtesy of Researcher
Note the Fox 12g 2 5/8" chamber was intended for 2 3/4" roll-crimped shells.
The pressure of period 1 1/8 oz. 3 Dr.Eq. (1200 fps) loads with Bulk Smokeless (DuPont, "E.C.", and "Schultze") was 7000 - 8000 psi; with Dense Smokeless ("Ballistite" and "Infallible") 8500 - 10,000 psi (similar to today's loads)
Use of loads with similar ballistics of course assumes the absence of barrel defects (requiring a bore scope) and adequate wall thickness (requiring a wall thickness gauge and the ability to accurately use it).
That is not to say the head of the stock wood might not benefit from lower
recoil loads.
And BTW from the 1884 hammer gun and 1886 hammerless, the L.C. Smith 12g chambers were cut 2 3/4".
