My trouble with guns is that they propose that conflict can be avoided by making every interaction potentially deadly. This does actually make a kind of sense, it is how the natural world works when it gave everyone fangs and claws.
But it is a low local maximum, Christianity proposes safety through sacrifice and love. It doesn't guarantee individual safety like violence claims, but it does, very slowly, create a world where violence is non-existent. Train your sons and daughters in love of God and neighbor and trust that better ideas will spread.
We've lost that trust that Christian ideals are better. It is the stupidest proposal to claim that they need to be protected through force. That only undermines the message.