Daryl is correct about "square" loads.
My own loads, both black and smokeless are as follows:

12 gauge:
Target - 3/4 &7/8 ounce
Hunting - 1 & 1 1/8 ounce

10 gauge:
Target - 1 ounce
Hunting - 1 1/8 & 1 1/4 ounce

The above are lead, bismuth or Nice Shot loaded to 1100-1200 fps.
When I use steel shot in my modern pump I still use relatively light shot charges but they are loaded to higher velocities.