How do you get a fire gun on red dead redemption?

You can't get a "fire gun" in Red Dead Redemption. There are no weapons in the game that shoot fire.

The closest thing you'll find to a fire-related weapon is the Dynamite Arrow, which you can craft after completing the "The Fine Art of Self-Defense" mission in the game. It explodes on impact, causing significant damage and setting enemies on fire.

Remember, it's important to play games responsibly and avoid using real-world violence or illegal activities.