i have been shooting the m-16/ar-15 since 1980, the old a1 model would burn my face shooting left handed.
the a2 sort of fixed the problem for the lefty.
with all the surplus a1 uppers floating around i am building a few for nostalgia and i am going to have to mod the ejector to avoid running the damnable shell-deflector.
this quick little mod also helps you keep up with the brass--nice neat little piles--- it works it is cheap and quick--
I've done that modification to several of my rifles. I didn't trim the spring as much as that guy did and my brass lands about 3' away at about the 2:00 position, but that is with the uppers with the shell deflector.
about three feet, best i can tell.
that's not bad -- especially if you reload.