When I began reloading in the 1960s the dominant trap load was a Federal paper hull, Federal Primer, 23 grains of Red Dot, a nitro card, two Felton Blue Streaks and 1 1/8 ounce of shot. Then along came the little PGS (Plastic Gas Seal) from Alcan to replace the nitro card and we could drop the powder charge to 19 grains for our same 1200 fps.
Looking through some of my Father's old loading manuals --
Ideal Handbook No. 38 (1951) gives load information on page 165 for DuPont Bulk, DuPont M.X. and Hercules Red Dot.
Ideal Handbook No. 40 (1955) gives load information on page 131 for AL7, AL5, Super M Ballistite, Acapnia, Nike, M-B, Red Dot and Herco.
Volume 1 of Reloading Information from The American Rifleman (1953) gives load data for Red Dot, DuPont Oval, Hercules Herco, Hercules Infallible and DuPont M.X. A lot of their load look pretty hot to me.
