There are some practical problems: 1) Steel core ammunition is illegal for use in handguns since its armor piercing. Banning lead without relaxing rules on ste

There are some practical problems: 1) Steel core ammunition is illegal for use in handguns since its armor piercing. Banning lead without relaxing rules on steel would create legal problems. And in some states steel core is illegal in all types of firearms. 2) Steel is more likely to spark if it hits a rock, for this reason it's banned in ranges out west and National Forest/BLM areas due to the risk of forest fire 3) Ammunition is out of stock everywhere and it would would definitely cause shortages and price people out of the market. There are millions of people who need ammunition not only for hunting but pest control, wilderness self-defense, and so on. 4) Someone more knowledgeable than me may argue this but it may not be as humane in some cases, since lead is designed to tumble and fracture killing the animal instantly while steel is more likely to go right through a target.