Well, problem is that it's more of a slow time release thing with lead in the brain. We're still dealing with the fallout from lead in paint and water pipes that were banned decades ago but it takes a while for the lead to leech into the brain, so they don't tend to get dumber and more aggressive until later in life. So the people touching lead ammo will probably get worse as they age. Of course there could already be significant overlap with the lead paint and lead ammo people. In which case they're probably just fucked.

So it might help, but it will take a lot longer than we'd like.