My brother does this. He only has five talking points, three of which involve guns, gun parts, and bullets and the rest is what he’s going to do when “shit hits the fan” and anything involving an engine. He has the personality of a bag of milk, so I stopped talking to him and cut him out of my life (it was more than just this that lead me to do what I did, but just listening to him rant on and on and on about guns was damaging to my mental health).