MODULE { name = DYJMachinegun ProjectileType = bullet //keyFire = z <<<<< keyFire = z <<<<< BulletMass = 0.45 BulletDrag = 0.03 BulletPower = 120 RocketPower = 10 recoilreductionfactor = 0.007 fireRate = 0.08 lackofkrakensbanontrailrendererscompensation = 0.1 rotationSpeed = 1200 isGatling = true heatProduction = 800 ProjectileFileLoc = Parts/DYJgau19/Bullet/ CasingFileLoc = Parts/DYJgau19/Casing/ } it worked for me because both of the keyfires were set to the same key which worked for me ^