[Austin W Hogan]

Shooters generally rank loads on a shotgun by chamber pressures found in catalogs and loading guides. Pressure induces stress on barrel and breech, but the weight of shot produces the stress on other componenents. It is possible to compare stress from gauge to gauge by comparing the length of the shot column; an equal length shot column produces the same force on a gun of any gauge.
Some people talk about a "square" load, which is a shot column as long as the diameter of the bore. The attached table is based on sparse data from order books, hang tags and ammunition catalogs but it appears consistent. It appears that King preferred loads of less than .8 bore diameter length for Parkers. There are some exceptions but they are small; for example the 1 1/4 ounce 12 ga live bird competition load.
The loads of length less than .8 bore diameter are shown in red on the table.

Best, Austin