Things They Should Invent: target-shooting guns that can't kill anyone

Whenever there's talk of tightening restrictions on guns, people are always like "OMG, but target shooting! It's a sport, ergo it's a good thing!"

Now my first thought in response to that is "But why don't you just not do target shooting?" But I feel that way about all sports, so let's assume for the purposes of this post that target shooting is a reasonable activity.

What they need are guns for target shooting that fire some sort of special bullet that can't kill a person. I don't know enough about guns to get more detailed than that. But target shooting guns, which would be perfectly legal for sporting purposes, could only fire special harmless bullets and would be incapable of firing bullets intended for killing. Then there would be no excuse for having killing guns.

Added bonus idea: anyone who turns in a gun intended for hunting and waives their right to hunt for the rest of their life gets a lifetime supply of free meat.