What's the REALLY good stuff? I'm a noob. Still learning
Basically you pay a big premium in Massachusetts for a fully built rifle, or the receiver that technically is the "gun" (someone correct me if I'm wrong) if it was made prior to 1994. It means that you can add a bayonet, grenade launcher, suppressor, collapsible stock, et. al. Is that stuff good stuff? I suppose, but you can still build a very good AR without that crap.