Ok, I drove my AMERICAN MADE TUNDRA BUILT BY A TEAM OF ALMOST 3000 AMERICANS IN TEXAS to the range today, and took a 12" piece of 2" black pipe that had a 3/16" wall thickness.
Used a cylinder bore choke, and two kinds of ammo, Federal bulk, 1 1/8 oz, 7 1/2 shot, and Federal target, 1oz of 7 1/2 shot.
At 15 yds, both reliably knocked the pipe down.
At 20 yds, the 1 1/8 oz reliably knocked the pipe down, but the 1 oz load just made it teeter. It did not go down.
At 25 yds, neither knocked the pipe down.
At 15 yds the pipe was knocked back about 2'
Each distance was shot with 5 rounds.
Didn't do it, but I suspect shots at the outer edge of the pattern at any distance other than point blank would not knock down the pipe. It would have to be center pattern.