12g 2 1/2' and 2 5/8' chambers were proved for a maximum service load of 3 1/4 Dram with 1 1/4 oz. shot. (1220 fps); the "standard" load was 1 1/8 oz. 3 Dram
12g Black Powder pressure
1 1/8 oz. 3 Drams (1200 fps) of DuPont FFFg (82 grains) was about 5000 psi.
1 1/8 oz. 3 Drams Curtis & Harvey’s No. 4, T.S. (82 grains; somewhat similar but not equivalent to medium grain FFg) was about 6500 psi.
RST 12g 2 1/2" shells; fps and psi
Ultra Lite 3/4 oz., 1125, 4400
Falcon Lite 7/8 oz., 1200, 5400
Maxi Lite 1 oz., 1125, 5700
