Guys I researched the steel shot issue when I used to live in Naperville. There was a trap range within walking distance of my house that a local resident tried to get shut down by playing the environmental card (I used to be an environmental consultant and his lawsuit was total BS, but that's another story). Anyhow, all he did was make it so we had to shoot steel or non-toxic shot (and finally after causing all this trouble, the SOB turns around and dies, how inconsiderate is that!).
I measured the petals on the steel shot wads and compared them to the wad petals used with lead shot. The steel shot petals were much thicker, so much so that the petals alone could compress more than enough to pass through a standard full choke. Before I became totally bored shooting trap and quite the game, I shot steel throuh several American guns, a 12 bore Nitro Special and a 12 bore Stevens 311. Neither gun appeared to be hurt in the least using #7 steel shot.
Steve