Don't worry, rgrx1276, I am going to post photos of real XM-21s, M-21s, and my M-21, later this weekend.
I don't know where you got your erroneous information about items 1,2,3 above, but I got mine personally by handling all these weapons, and talking with other officers who used various things, as well as three close friends who were armorers and snipers from 1936, through USMC Pacific Theater, Korea, and Vietnam. Two of them (US Army) are still around, so they can fill in a lot little details for me.
I also visit the military museums, and use the official papers of the various branches, to learn more, and to back up what I say to uninformed skeptics. As I found with my very first posts here, even the direct quotes and citations from USMC sniper development documents would not raise an apology from the web trolls who had called me names.
