I found them fascinating. The 3in buckshot result was compelling as per Federal (personal email); a shot charge achieves full velocity in about 16in of bbl. The long bbl just assists follow through (and seemingly lethal hits w/3in .00 @ 75yds).
Fun Fact: This gun was the 2nd 12ga I ever shot (same bbl length). This first was a 37 Winchester which rang my bell. The "Long Tom" de freaking stroyed a beer can @40 with #9s with "zero" recoil. My uncle bought it for turkey shoots in the Hills. He didn't have inviting attributes.
I believe the gun was disallowed.
That is all.