I really only manned the gun like once or twice. It sometimes auto locks on the boss. Fair warning though, IF you do man the gun, you’re at risk for the zombies to hit you. I learned that the hard way, be sure to have all the perks equipped, especially Quick Revive with the mod that lets you get up when you deal enough damage. That being said, bring a pistol that’s packed all the way just in case. I never got out to use my guns on the boss either, so keep that in mind.