Ted;
I am in full agreement that black did stay around a good while after smokeless was introduced & was used by many both for economy & familiarity. Early Ideal handbooks which were the primary loading instruction manual available in those years did not recommend loading anything but black or bulk smokeless. Loads were somewhat limited by shell capacity, however, fairly stiff loads with 1¼ oz of shot would fit even the 2 5/8" hull with a roll crimp.
Now I may be wrong on this (would like to be shown if so) but I have before me an old Hercules loading manual. Two hand-picked loads; both with WWAA hulls & Win 209 primer & using WWAA wads are;
#1 - 18 grains powder X with 1 1/8 oz shot @ 1200 fps @ 10, 400 psi,
#2 - 25 grains powder Y with 1¼ oz shot @ 1220 fps @ 8,400 psi.
My take is in spite of the 2K lower psi load #2 will put more bending &/or stretching stress on the frame than will load #1 as it is moving a heavier load at a higher velocity. Load #2 is listed as a 3¼ dram equivalent
I will stick my neck out even further & say if one loaded 89 grains of black behind 1¼ oz of shot & reached 1220 fps even if the psi was only 6,400 it would still have put essentially the same stress on the frame.
Sounds to me as if the Tobin was simply under-engineered from the git-go for either Black or Smokeless in anything except very mild loads.
