Having shot thousands of military 303 through several No 1 and No 4 rifles, I have never seen a muzzle flash. Granted, my shooting has never been in the dark, only low light every now and then. Or my eyes are deceiving me, which is entirely possible.
Try it with a No5 at dusk it is impressive.
Mine are not the best, but they are not too bad. I can think of lots of Enfields I'd rather have but instead of constantly striving for more, sometimes it's good to be satisfied with what one has...