I would say to kill other people. In this light the gun was simply the continuation in lineage of the bow & arrow, club, sharp stick, knife. Any of these things can also be used for constructive, non-murderous purposes. The point I'm making is that an item does not have murderous intents. That the gun is a very effective tool for carrying out murderous intents is not the same thing. It's an important distinction.

-Zeke