as it currently stands, there have been no new machine guns able to be made by regular everyday people since may of 1986 - google and read the mcclure volkmer firearm owners protection act
of course you can become licensed to manufacture full auto firearms for military and law enforcement but there are ALOT of headaches involved with that, but certainly doable. The ATF has been CLEAR that it requires you to actually be in the business of manufacturing firearms, and you may not do this as a hobby only, you actually have to be in the business. It will cost you money for the manufacturers license, and an extra $1000.00 for the SOT tax that allows you to make MGs as post may dealer samples. The tax will need to be paid yearly. You will need to find someplace that will rent you a building and you have to let them know you will be making machine guns because the atf will DEFINATELY tell them upon the interview process. You will need to buy insurance for your business, and all kinds of fun stuff before you ever become licensed or are able to make a single firearm. The building must be zoned, and many places wont let you do this out of your house. If you do live in a place that lets you do it out of your house, then you open your house to the government to come in anytime they wish to have a look around.
also mentioned above, you ARE able to do this if you buy a firearm registered to the NFA before may of 1986 as a transferable gun. This includes sideplates also as mentioned above.
to buy a transferable firearm, first you have to live in a state that allows them
after that you will have to purchase one, and send the money to the owner of the NFA item which will start the paperwork process. You will need to have it signed by your chief law enforcement officer stating that he knows of no reason you shouldnt have it. After the law enforcement endorsement, then you send the form 4 in with 2 sets of fingerprints, a form stating you are a us citizen, clear recent passport photos, and a check for $200.00. You will go through an extensive background check by the FBI. If you pass that, the forms will be returned to the inspector and you will then need to pass the ATFs inspection criteria. Once all that happens, a form 4 with a $200.00 hand canceled tax stamp will be mailed to the person who owns the NFA item. Once he gets the approved form 4 with your passport photo and hand canceled stamp on it, he will hand you the firearm or NFA item.
If you live in a different state, you will need to find a NFA dealer locally that will receive the NFA item for you. This usually requires an extra $200.00 tax plus a transfer fee because it has to transfer from the original owner in a different state to the NFA dealer in your state, and then from the NFA dealer in your state to you which also adds time to the whole thing. it can take a long time some times, and the wait will kill you. I recently went through a transfer and it took 4 months
so, in a nutshell, you have 3 options the way i see it
1. become a licensed manufacturer and pay the SOT tax and jump through all the MANY hoops to be able to legally manufacture new MGs for law enforcement and govt acencies only
2. buy a transferable machine gun or NFA item like a sideplate registered to the NFA registry as a transferable gun before may of 1986 and pay the fees associated with that, and jump through all them hoops
3. if the scotus rules in our favor on heller vs DC under strict scrutiny, you can hire a lawyer and try to get the 1986 FOPA thrown out on the grounds of its unconstutionality and pay and deal with all this headache(good luck on this option)
either one of these three options will be expensive, and full of bureacratic red tape and headaches, but your only hope of doing this
research the mcclure volkmer firearm owners protection act of 1986, and if youre interested in maybe becoming a licensed manufacturer, then look up the machine gun dealers bible (which will give you information to help you towards getting your manufacturers license with SOT tax paid for govt and LE samples)
clear as mud?
hope some of it helps and isnt too repititious