Thanks for the feedback everyone! Primary reasons are health-related - trying to minimize my exposure to lead dust while at the indoor ranges that I frequent. Really I just need to start shooting outside more often...
Your greatest lead exposure by far is 1) indoor ranges with poor cleaning and maintenance plans, and 2) indoor ranges with good cleaning. Take a pair of white cotton gloves with you and swipe any horizontal surface. That gray stuff on the gloves is lead dust !
It's not the small amount of lead dust and fumes you create that's at issue, but what's been done before you arrive, all being stirred up by fans and people walking around.
...and I'll keep my SHTF mags full of FMJ.
FMJ, or "military Ball ammo", is made such that raw lead is exposed on the base of the bullet. When the powder ignites it burns hot enough to liquefy and vaporize some of that lead. You breathe those vapors, and what you don't breathe settles on horizontal surfaces. In the photo below, the Montana Gold FMJ in the second position is very typical...
JHP ammo is the same copper cup filled with lead.
The difference is that the exposed lead is on the nose of the bullet and the base is completely sealed. Therefore, the hot burning powder is
not in a position to vaporize the lead. The 155gr JHP, on the far left, is typical of this type construction...