Turn-of-the-century Live Bird loads were usually 1 1/4 oz. 3 1/2 Dram Eq., or more;
Sporting Life, Dec. 4 1897
http://library.la84.org/SportsLibrar.../SL3011024.pdf
J.D. Gay...used a Parker gun,
4 drams Hazard “Blue Ribbon” (Bulk) smokeless, in Leader shells, a Winchester factory load.
In the 1927 Western Cartridge Co. advertising flyer for the "Super-X Long Range Load" by Capt. Chas. Askins, the 12 Gauge Duck Load is described as 1 1/4 oz. with 3-1/2 Drams (Dupont Oval) with a muzzle velocity of 1400 fps (modern numbers are measured 3 feet from the muzzle and would be about 1330 fps) and a breech pressure of 3-3/4 tons or just below the current SAAMI 12g maximum of 11,500 psi.
And a steady diet thereof in a 100 year old gun may do this
So it would seem reasonable to be proactive and glasbed or reinforce the head of the stock in some way
before using boomer loads
Staple and fresh acraglas
or the Parker "dumb-bell" wood insert courtesy of Dean
Threaded Mode