Re: Identify this trigger
To my knowledge only a few ARs are machined in such a way as to block installation of an auto sear. Yes, it would be required to convert. However it is a moot point. As the law has been explained to me, you cannot install any part from and m-16 in an ar-15 whether it makes it full auto or not. Guys used to do this because m-16 parts were cheap. BATFE considers possession of m-16 parts and an ar-15 as "constructive possession of an unregistered machine gun" (i.e. felony). Personally I would get rid of them.