According to this article (full disclosure: I wrote it) lead-based ammunition is a well-known threat to Condors and other scavengers, and may have negative effects on humans who unknowingly ingest bullet fragments.
Anecdotal evidence suggests that lead-free ammunition performs just as well as lead-based ammunition, without the potential side-effects, and lack of adoption is largely due to habit (we like to use what we have always used).
So, my question is two-part:
- Are there documented performance differences between lead-based vs lead-free ammunition?
- Have any hunters who have used both noticed a marked difference in performance?
NOTE: I re-posted this technical question for the firearms experts at firearms.stackexchange.com - if you have an answer, join in.