GUN turrets are stationary weapons akin to the Cell Cannons, able to shoot out red bullets.
To use a GUN turret in gameplay, the player has to approach it and press //. Once in, they player can use the control stick to aim the shots with the "X" mark on the screen (which indicates where the shots will land) and press // to fire. To leave the GUN turret again, press // again. The GUN turret is not indestructible though, and enemy attacks will deplete its health bar. Once its health bar reaches zero, it will explode and force Shadow to leave it. It will also drop a Heavy Machine Gun, which can be used against enemies.
When mounting on the GUN turret, it has unlimited ammo and no fire-cap applied. Players can tap // fast enough to exploit maximum damage output when taking down the President's escape pod.