Control the environment thru legislation and the enforced feeling of guilt about "environmental justice" and you have a great chance to successfully control ammunition. Then the guns just follow. Price ammo beyond the economic reach of most shooters and it's "Mission Accomplished". Invoke the sad, tragic and extremely false plight of the Kalifornia Kondor ingesting lead core bullets or the lead fragments from them in the carrion they eat, and well.........the poor pterodactyls are falling like rain.
Have you ever seen a Kalifornia Kondor auguring in from lead-poisoning? Have you ever seen a Kalifornia Kondor? Neither have I. And that is because a special "state unit" of zoo keepers keep them in captivity and release but a few every now and then. Most of those released end up being fried by the 44,000 volt high-tension electric cables running across the state. Lead core bullets will just have the effect of electrocuting condors, especially those from Kalifornia. Consider them the airborne Delta Smelt of the Environmentalists.