Bismuth is a perfectly acceptable alternative to lead for use in projectile weapons, however the cost of the metal makes shooting with it prohibitive.
The obvious connection with surface water body contamination with lead compounds and sport waterfowl hunting with firearms is the reason for legislation that aims to mitigate this exposure as much as possible. It is not legal to use unjacketed lead shot to hunt waterfowl. One must use copper jacketed lead shot (Very bad for gun barrels, especially antique black powder models, which have softer steels in the barrel which become eroded from the abrasive action of the copper jacketed shot pellets), or use the expensive bismuth shot.
Considering that bismuth is not that rare of a metal, I really don't understand why it is so expensive per pound, but it is. It may have something to do with bismuth having more applications in medicinal preparations (Peptobismol is bismuth subsalicylate, sodium saccharine, water, red #40, Blue #2, and wintergreen flavoring.) and in chemical processes that drive up its demand, but I would need to see data to that effect.
Edit:
The point to the above that I got lost in the particulars of-- Shooting ranges need not necessarily be contaminated with lead, they typically are because of the lack of affordable alternatives, even though suitable alternatives most certainly exist.