locked projectiles, or onplayertouch>player>spawnprojectile [tankshell for boom]
or variables
onactivate>player>setvariable [turret][5]
onactivate>self>firerelay
onrelay>self>ifvariable player [turret] equals [5]
onvariabletrue>self>firerelay
onvariabletrue>player>spawnprojectile[rocket]