I bought a box of these on a whim 2 years ago. At 8 feet, they go through the first layer of corrugated cardboard. And if you're shooting them out of a rifled barrel, the shot donuts pretty harshly. I think I still have about 35 rounds on it, maybe when I head out to the range tomorrow, I'll take them along just to hoof downrange and get rid of them.
They kinda make me miss the $12 or so I paid for them.
Edit: Another issue I had with them is failure to extract. It seems that when the crimp in the brass opens up, it grabs into the rifling and gets the shell stuck in the chamber. I'd love to find a cheap smoothbore .22 to see what they're truly capable of.