I forgot to add that The upper is by Olympic. There is muzzle flash, but not enough to be distracting, However I have not fired this upper at night. All of the bullets that I have fired through this upper were 55 grain. I have had under .5" groups at 50 yards with 55 grain bullets. This upper will handle a heavier grain bullet with no problem. I have not been able to get to a longer distance range. Thanks for your intrest.