Okay.. When i do chain fire it works for like 10sec - 20sec and then it gone to normal shooting.. i had this problem alot.. dont know why.. it works sometimes and sometimes no
Actually this is just like Vaygaar said. FL engine is old, so every time when NPC entering your scanner range, player jumping into your system, just any minor lag that lasts for 0.01 sec your gun firing stopping and firing again. you wont see it because its happens fast usually. if you had reaction as Fly have it - youd noticed it.