By my calculations, you need 140 cubic inches per stand.
The area of a triangle = base x height / 2
A 4" equilateral triangle has a height of 3.5"
4" x 3.5" = 14" / 2 = 7 sq in (area of triangle)
Multiply area x height to obtain volume:
7 x 20 = 140 cubic inches per stand
I don't know how you would convert this to pounds of shot (without knowing the specifics of the material), but it should help.
Jim D.
The area of a triangle = base x height / 2
A 4" equilateral triangle has a height of 3.5"
4" x 3.5" = 14" / 2 = 7 sq in (area of triangle)
Multiply area x height to obtain volume:
7 x 20 = 140 cubic inches per stand
I don't know how you would convert this to pounds of shot (without knowing the specifics of the material), but it should help.
Jim D.