Originally Posted By: 2-piper
....a 12 = 1.0565oz (close aplenty to 1 1/16oz)....

....There are your Square loads, how many folks you reckon shoot them??

In the twelve, 7/8th. to 1 oz. loads seem pretty popular. Once a bit of bore diameter is lost for the thickness of the wad, those could be the mythical square shot column. I always thought the 'square' was sort of a rule of thumb balancing volume and the concept of fluid flow through the barrel with respect to flyers that blow the pattern, but I doubt it matters much.