Also, one of the biggest improvement in hunting cartridges are the 'wads' which used to be plastic, and now are wool or fiber, in any case, biodegradable -- the steel cartridges don't have these as they need a 'cup' to protect the barrels as the shots go out, so you leave big pieces of plastic all over, to be ingested by /other/ wildlife, potentially.
So no real perfect solutions so far; Legally you can't shoot lead anywhere near waterways so we have to use steel, but for example last year I shot a duck, fair an square, nowhere near "out of range" -- this was a 'dead duck' -- we looked for it for 20 minutes to discover it had gone to ground and was NOT dead, it had been broadsided, but some pellets had gone thru the poor bird, and some of the pellets were in the feathers, because they didn't have the energy.
As much as I like hunting my supper -- and I hunt to fill the freezer so I don't ever have to buy chickens -- I really hate to be in that situation where I inflicted undue pain for no reason other than some city environmentalist (who probably sit at his desk all day) making wide ranging decisions like this.
It's going to be difficult to find a metal as "good" as this job as lead; I would love for steel to work really, perhaps we could somehow devise a 'steel shell around a lead pellet' -- that would allow 1) killing power 2) protection for lead leakage and 3) loads of time to use magnets to recover it from pretty much anywhere... I realise a good part of the energy of lead hitting a target it when it splatters, and the steel shot won't do that, but it ought to be better...?
Anyway, that evening we had duck, and we toasted the duck; unsuitable apology as it is.