Gun Turrets consume 150 Metal and take 5:00 minutes to build. To shoot it requires hydrogen to be in its cargo hold, which can be transferred in by the player manually.
Each shot does 500 damage and travels in a straight path, thus it is possible for it to miss. Compared to the ship's Missile (2000 damage) or the ship's laser gun (5000/sec) it is fairly low damage. Because shields recharge as long as there is a supply of hydrogen, using guns to take down shields is fairly ineffective if one is alone.