dcmdon
NES Member
To actually do what you want legally you need an 07 FF (as well as the attendant MA licenses), and you ain't going to have one of those in your house in Mass, unless you're zoned in really weird area where you can have an outbuilding....
Remember the issue with a home FFL in MA is the state license. You don't need a state license to get an FFL. There are plenty of other ways to engage in commerce in firearms without doing retail transfers.
The ATF has issued guidance that if you do basic upgrades to an existing gun and offer it for sale then you are doing manufacturing.
When I had my 07 FFL in CT, I would get in firearms that were non-compliant with the pre-2012 AWB and make them compliant, then offer them for sale. This is manufacturing per the ATF.
Another example is if you buy a milsurp rifle and install scope rings and a scope then install a spotter stock. This is manufacturing per the fed.
When I applied for my 07 FFL I provided this kind of documentation. I stated that I would be doing only light assembly (which is what putting together ARs and Glocks is by the way) using water based solvents.
My 07 was a slam dunk. It's the same in MA. In fact the zoning regs are easier in MA. Once you have your 07, it's simple to get a Class 2 SOT. You just pay it. There is no application.
At this point you have an 07 FFL with a Class 2 SOT and you can manufacture a machine gun 100% legally.