Colt lost a trademark infringement lawsuit against Bushmaster
back in December of 2005, so it's highly unlikely that they'll be
pursuing further legal action against other AR-pattern rifle
manufacturers, either at home or abroad. And even if they wanted
to, I doubt Colt has the financial and legal clout to take on a
state-owned enterprise like Norinco.
The AR design can, for all intents and purposes, be considered
public domain; witness the plethora of companies (some of whom
aren't even primarily in the firearms business!) manufacturing
parts for the rifle.
