There is no bayonet lug on this particular model Tyler. The bayonet model would look like this : google.com/search?q=mossberg+590+bayonet+lug&source=lnms&tbm=isch&sa=X&ved=0ahUKEwi7vY3Uq8zdAhVMwlkKHaFDCcgQ_AUIDygC&biw=1920&bih=938#imgrc=3Gnhqd9qSzmokM: