Here's one for CT residents.
Background: CT Law specifically bans specific firearms, by name, as banned assault weapons that cannot be transferred or possessed in the state unless they were registered prior to Oct 94(?). We also have a feature count that would identify a banned firearm if it was made after 9/94. Additionally, a select fire MG is also considered an AW and banned by feature. CT law also exempts registration and transfer restrictions for firearms that are in an AW configuration providing they were made prior to 9/94 and not on the named list.
I have a buddy of mine who owns both an RDIAS and a registered AR15 Sporter. Since the Sporter is already considered an AW and properly registered, installing his RDIAS into his AR15 host gun, he can maintain the select fire feature, as he is not creating a "new" assault weapon. This is per the SLFU.
Now, logic would dictate that if someone owns a non-named, pre-9/94 AR15 style rifle in an AW configuration that is not subject to registration or transfer restrictions, it would be legal to install an RDIAS and maintain the select fire capability, right?