I was skeptical for a long time. Over the past year, several things have changed my mind:
1) A few guys at the range have asked me over the years "if lead is so bad for condors, why are there still so many turkey vultures around?" Until recently I couldn't get a good answer from my biologist friends. Last week, a Yurok biologist told me that they have "documented lead toxicity in vultures... there are just so many of them around that no one notices if a few die."
2) The same biologist showed me an x-ray of a deer carcass shot with conventional lead ammo. At high resolution, there was considerable dispersion of lead fines in the carcass well beyond from the bullet track. Most of it wouldn't be readily visible to the eye.
3) See the article at the link below, CBD has credibility with some of the best lawyers I know so I take them seriously. There are about a zillion additional references linked within the article:
https://www.biologicaldiversity.org/...Ammunition.pdf
End result is that I'm now minimizing use of uncoated lead... coated bullets for quantity reloading + glove up, and copper for sighting in and backcountry use since any take of wildlife here now requires non-lead. I even cull invasive bullfrogs with CCI copper .22 LR.