This from the latest Watchtower Question from Readers:
"How a Christian chooses to protect him- self, his family, or his possessions is, of course, largely a personal matter, as is his choice of employment. That said, Bible principles reflect God’s wisdom and his love for us. Out of regard for those principles, spiritually mature Christians choose not to keep a firearm for protection against other humans. They know that true and lasting secu- rity comes to those who demonstrate trust in God by living in harmony with Bible principles."
The whole article is basically a discussion of principles, but do they leave it to the brothers to make their own decision based on those principles? NO, they proceed to make a LAW: Christians choose not to keep firearms.