As others alluded to indirectly, the original Colt Model R6000 AR15 SP1 Sporter rifle of 1964 was much more similar to then current production military AR15*/M16’s than later AR15’s. Various changes were made over the years some at BATF insistence to make it progressively harder to convert to selective fire or ad hoc full auto, to where you can convert one later ones if you’ve got enough tools and expertise…but you can also build one from scratch if you’ve got enough tools and expertise.
*the selective fire weapon fire adopted by the USAF in 1962 was officially designated ‘Rifle, AR15’. The Army also only adopted the designation M16 after combat trials during which they also called it AR15. The R6000 was the civilian version of it. Only later on did ‘AR15’ come to refer just to semi-auto civilian versions, as most people now use the term.
From this: https://www.atf.gov/file/58146/download
I take that certain parts can be interpreted as constructive possession of an automatic weapon. Arguably just owning them could be serious trouble, for sure owning them and also the bolt-carrier they work with seems to invite a very negative interpretation of the situation.
It is very easy to convert a semiautomatic AK to full auto (easier than an AR15, and even that is within the capabilities of many hobbiest metalworkers), I have always made sure to have nothing that even looks like the parts needed to do so in my house.
Even if it were legal, I would never want full auto guns. Noisy, expensive, and, frankly, gauche. Never understood why anyone would want a bumpstock either.
ATF Technology Branch has released a letter of clarification in response to an inquiry from Colt. They basically said that if the parts would make the firearm fire full auto, it is illegal. If the installed parts would not allow the firearm to fire more than 1 round per trigger pull, then it would not be unlawful to posses. Since an M16 bolt carrier alone would not affect the firearm in that way, it is legal to install in an AR15. Possession of the full aut bolt carrier, along with the other necessary components, would be a violation.
Plenty of people prefer the M16 bolt carriers because they are heavier. They seem to shoot smoother with less recoil.
Automatic small arms are really only useful in the niche context of infantry combat doctrine. 99% of gun related crime is small time and I mean really small time. It’s not something that these guys spend time planning in an organized way. Their criminal activity doesn’t involve throwing smoke grenades or digging holes or calling in airstrikes. Nobody’s shooting it out in the streets with rifles. It isn’t the Bonnie and Clyde days anymore where gangsters could conceivably exchange fire with police officers and make a getaway and live to ply their trade another day in an environment with no internet, no GPS or cell phone tracking, very limited surveilliance, and far greater odds of successfully disappearing off the grid temporarily. People like the guys in Heat do not exist.
Tom Wolfe said it best in The Bonfire of The Vanities:
Might be easier to use the “ghost gunner” CNC machine and a blank lower receiver. Get a file from the dark web that cuts the correct pockets and holes in the lower receiver for an m-16 instead of an AR-15. This would put it into reach of a hobbyist without much machining experience. Here’s an article on it, where a clueless journalist got it to work.
I will amend my opinion that it’s easy to say it’s moderately difficult, given the need for special tools, but still definitely doable without having any particular talent.
This is pretty much in line with Corry El’s last statement, though.
Yes, that $1500 machine would theoretically allow a novice to “modify” an AR-15. But, as shown in the video, it would also allow you to build one from scratch.
It is possible to have advanced skills that outweigh one’s lack of equipment, or sufficiently advanced equipment which outweigh one’s need for skill. But once you’ve got enough of one, the other or both… you have enough to make a machinegun from scratch. So “modifying” becomes a moot point.
You don’t have to start from scratch to make one. “80% receivers” are legal to buy without an FFL* and jigs help in the machining needed to complete the job. It’s easier or harder than you might think, depending on your politics. Just don’t get caught with the finished product. As alluded to above, with enough bux you can legally buy an automatic firearm, so far as the feds are concerned; your state may have a different view.
I consider an 80% lower “building from scratch”. I’m not picturing anyone actually starting with ingots of aluminum, but I realize others might have a different definition. SamuelA’s link addressed the subject of 80% lowers, and showed two ways of milling–the traditional method with a drill press, and using a CNC machine. You’re right about jigs, though. I don’t think he used them in the video, but there are jigs and kits for both M16 and AR15 lowers.
Not really applicable to the full auto AR-15 OP of this thread, but since 80% lowers were mentioned I wanted to add that there are 80% lowers available for “Glockish” pistols as well as 1911 style pistols.
You can also build 0% AR-15s starting with nothing but a can of plastic resin and a set of molds.
Further, the two offenses don’t have to be prosecuted and the interem penalty imposed. For example if they find out that you hit the Gambini gang last week with a machine gun and hit the Caparzi gang this week, that’s two crimes of violence with a machine gun and mandatory life imprisonment.
As far as PMIA federal prison, in my practice I have had some experience dealing with the feds and their prosecution of machine guns. At least in this area, if you get caught with a machine gun, they investigate the reason for your possession. If they believe that you are using it for criminal purposes, they will come down on you like a ton of bricks and press for every charge they can find.
If they believe that you are just some gun guy who thought it would be cool to have a full auto to blast away at shit on the weekends, then they don’t look for prison time. They are satisfied if they can convict you of some crime (even if it is the possession of the machine gun) to make you a prohibited person so that you cannot own guns anymore. Then they argue for unsupervised probation.
It is my understanding that new semiauto firearms are required to fire from a closed bolt, for safety and to make it harder to convert (I think Ian on Forgotten Weapons YT channel said this).
An open-bolt firearm (most submachine guns) simply strips off a cartridge, chambers it, and fires it with a (usually) fixed pin in one operation–it’s easier to bypass a sear to let that bolt keep cycling.
Converting an AR-15 to automatic is easy. Obtain the following M-16 parts: Hammer, trigger, disconnector, selector, and bolt carrier. All of these are direct replacements for the semiautomatic parts, and fit right in. The hard part is the automatic sear. You can construct a drop-in auto sear. There are little books, and probably online drawings, that show you how to make them. Drop one of those in, and you’re ready to rock and roll. Alternatively, obtain an M-16 auto sear. These will not fit in an AR-15. You’ll need to mill the inside of the lower receiver so that it will fit, and drill holes in the lower receiver for the pin that holds the auto sear in place. (You’ll have to place the pin holes precisely.)
Of course I have not converted an AR-15 to automatic. That would be illegal.