From: "John R Weiss"

snip

With "bird shot" (#7 or 8 lead), though, the trade-off would bethe
close-range "column of shot" effect vs lesser penetration. Even with a
cylinder bore in a 18 1/2" or sawed-off (highly illegal in most cases) barrel,



Under federal law the minimum barrel lengths are 18" for shotguns and 16" for
rifles. I know of no state law that furthe restricts length.

Dan, U. S. Air Force, retired