Well, as you know, in Mass you need a place to keep your records that is not a residence. ATF frowns on getting the FFL to enhance a personal collection. However, you can enhance your dealer inventory as much as you want. For a serious gunny, the 07FFL/SOT opens the door to full auto, suppressed and other neat stuff that can be for personal use. ATF wants you to make a profit, but they don't say how much. Just keep your paperwork in order and you are OK. If you don't want to sell anything in Mass, you don't need the state licenses, business cert. or any of that shit. ATF will be happy and the state and town won't even know that you exist. Have fun. Jack.