Originally Posted by Gbmaryland
So, if you were to purchase an AR reciever, it's regulated and in the systemm, like a handgun. However, if you build it out as an HBAR clone, it's not a regulated firearm anymore.
From what I understand you can not build an unregulated firearm out of regulated parts. In other words you can't build an unregulated HBAR with a regulated receiver. Once the lower is "in the system" it stays forever. I wouldn't advise building an HBAR like this and trying to sell it as unregulated in Maryland.