I had wondered about the caution to not use NATO ammo in the Handi rifle and didn't really see the whole picture to be able to understand NEFs position. Just recently, there was a post that reprinted a 1988 article from Rifle Magazine that tells the reason to keep that NATO stuff out of commercial guns.
Rather than repost the article, I'm just going to link to it and you can look at it if you're interested. It was posted 27 August 2005 at 9:36am, so you'll have to scroll down to it.
http://forums.handloads.com/forum_posts.asp?TID=7990&PN=1&TPN=1
