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The following arrived in my inbox from a dedicated, anonymous, unidentified, stealthy, unnamed, uncredited, unknown, mysterious reader:

Federal law allows individuals to manufacture their own firearms. Not only is it fun and rewarding, but you don’t need a serial number on the completed gun. No one in government need know about your firearm; a fact that gives the project tremendous appeal to gun enthusiasts worried about Katrina-style confiscation. (Where do you think the authorities got the info to go after the guns?) The only caveats . . .

The machine work must be done by the end-user—no contracting it out or having a friend do it. The finished firearm can not be transferred in ANY manner. No willing it to your kids. No giving it to a friend. If you no longer want it, after your inheritors pry it from your cold, dead hands, it MUST be destroyed.

There is a small, but burgeoning industry for people who want to start with partially machined parts. Components are available for ARs, AKs, 1911s and even some SIGs. The standard for this is set at the 80% completion point.

Once the receiver passes the 80% completion point, it is considered a firearm. If it is to be sold/transfered to the public, it must be taken past the 80% point only by a licensed, manufacturer and serialized upon completion. At, or before, the 80% completion point, selling or buying the partially completed lower is NOT considered buying a firearm and it is treated like buying a hunk of metal—no FFL required.

I purchased my 80% lower from An internet search will reveal several sources.  Depending on where you purchase from, the punch list for completion may vary. My tasks included carving out the pockets for the hammer/trigger system, the slot for dissention of the trigger, and the holes for the selector, hammer pin and trigger pin.

A proper mill makes the job easy, but jigs are available for the job to be completed on a drill press as well. Having never previously touched a mill in my life, I broke my machining cherry at a friend’s machine shop. While an experienced machinist can probably complete the task in an hour, it took me almost a full day.

Most of the time was spent learning. I needed to understand the basic concepts of machining and get in some practice before taking on the job lest I ruin my lower. I also machined very slowly, taking only 50 thousands of metal off at a time, to limit damage of any potential mistakes. The slow process and often repeated steps helped reinforce the learning process.

The firearms’ finish must be done by the owner. Metal finishing companies can not take in a firearm without a serial number; all firearms must be logged in and out of their bound book. My finish was a simple bead blasting, but any do it yourself process will work.

The 80% solution works. The gun fires perfectly, looks awesome and, best of all, it’s mine. All mine. And no one knows about it except me. And 700k TTAG readers, some of whom may wish to follow my example Without the advertising.

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  1. COOL!!! I had no idea that the 80% rule existed. I was aware that we could build our own, but always assumed we had to do it from “scratch”.

    • You may have a machinist mill your 80% but you must be there the entire time per ATFE.

      • You absolutely CANNOT have a machinist do your 80% for you – you must do the work, yourself.

        For that matter, per ATF Ruling 2015-1, you can’t even do it in a machine shop – you have to either buy the stuff, or borrow a friend’s hardware – and said friend must NOT be someone who uses his or her machinery as a business.

  2. “The finished firearm can not be transferred in ANY manner. No willing it to your kids. No giving it to a friend. If you no longer want it, after your inheritors pry it from your cold, dead hands, it MUST be destroyed.”

    Total BS. A guy local to me does a lot of 80% “build parties” where people can get guidance when building an 80% AR/AK while still doing it themselves. Many of the guns built at these parties have been successfully transferred. I think there’s even an ATF letter floating around somewhere that deals with it. Those two sentences should be removed so you guys aren’t spreading BS.

    • I mean no offense by this, but I don’t believe either one of you, because this sounds like something that I should really investigate for myself and to my own satisfaction.

      Here’s why: without outside proof (e.g. that letter you refer to), it’s his anecdotal “can’t be transferred/must be destroyed” against your anecdotal “yes it can, the ATF even said so, somewhere.” Without further evidence from either direction, if there’s incorrect information in the post, I’d prefer it be in the direction of legal safety, i.e. I’d rather think it can’t be transferred, and then be pleasantly surprised to learn different, as opposed to thinking it can be given away, and finding out I was wrong and potentially getting in lots of trouble. “I read it on a blog” is not acceptable in most states as a valid legal defense.

      In short, do your own homework. Don’t rely on anything you read, in either direction. At least, that’s what I do.

      • Individuals manufacturing sporting-type firearms for their own use need not hold Federal Firearms Licenses (FFLs). However, we suggest that the manufacturer at least identify the firearm with a serial number as a safeguard in the event that the firearm is lost or stolen. Also, the firearm should be identified as required in 27 CFR 478.92 if it is sold or otherwise lawfully transferred in the future.

        Scroll down, make sure to read it all. You can make guns and later sell them but you may not make them for sale.

        • Exactly. You can’t build it with intent of selling it, but selling it down the line is completely legal.

          I know for a fact they can be transferred because I’ve seen it happen at my local FFL.

      • This is 100% correct. The TTAG article has several legal faults, most of which have already been identified. So I’ll just summarize:

        1) There is no requirement for an individual to engrave ANYTHING on their firearm (serial number, name, etc)

        2) Firearms made from 80% CAN be sold/transferred just like any normal firearm, as long as you are not building them with the INTENT of selling them. That would make you a manufacturer.

        3) There is no requirement for firearms made from 80% to be engraved before sale/transfer. The BATFE says ‘should’, not ‘must’

        4) Firearms made from 80% CAN be shipped to be engraved and have finishes (duracoat, bluing, etc) applied. The BATFE considers this repair work.

        And for anyone like Matt who likes to do their own homework, the link that Pt provided is the reference that contains all this information.

        • Also on point 4, firearms only need to be logged into bound books if they are temporarily transferred (i.e. spend the night), if you wait there and they do it that day while you are waiting the firearm does not need to be registered in.

        • Just a note – Do your own research- You will find out that you can actually manufacture up to 5 a year to sell , and not come under scrutiny by the ATF . More than 5 a year and you have to do the license the tax the whole nine yards ,I cannot stress enough read ,read ,read ….. in a half hour of reading you can find out all the answers you need .

      • That is why you should always C.Y.O.A. and contact them via mail so you have a physical letter on department letterhead addressed to you about your specific case.

    • It is unlawful to transfer the completed, 80% lower without serial numbers. To be transferred, it needs to be properly marked.

      According to TacticalMachining, in order to be sold, it must be marked with:

      manufacturer (this would be you)
      state (your state)
      country (usa of course.)

    • Why wouldn’t my son inherit my property. He can easily say he built it, and who would be able to prove otherwise. There are no question marks because this is a rhetorical question.

  3. Even though you don’t have to serialize it, it’s not a bad idea to add some kind of identifying mark or number if for nothing else than to prove you own it.

  4. If the 80% build rule is true, I wonder if building your own lower in any way allows shooters in MA and CA to circumvent the restrictions on accessories by the AWB.

      • According to TacticalMachining, who sells 80% lowers, in order to be sold, it must be marked with:

        manufacturer (this would be you)
        state (your state)
        country (usa of course.)

        • Personally I would never attempt to transfer a non marked reciever, and from my research into it the ATF really does not want you to. The letter of the law is that it should, not it must, but that does not mean that Uncle Sam will let it happen. Those who have asked the ATF that I know of have gotten non-answers regarding this. I asked them specifically about transfering ones that I had marked per regulations (specifically to my nephews when they are older) and they advised me that it would not be a problem.

          Contact them by mail and save any reply you get. If and when I give a custom AR to my nephews with a lower I completed a copy of that letter will go with it.

        • Besides, why wouldn’t you want to put your name on it? You made it, be proud and let all who look at it see that.

      • I’ve spent enough years dealing with the EPA and DOE to confidently state that government agencies view “should” and “shall” as synonyms.

        • The Federal Plain Language Guidelines (page 25) referred to in the Federal Plain Writing Act of 2010, compel every federal department to “use ‘must,’ not ‘shall’” to indicate requirements.

          In DOD “should” has never meant a requirement, only “shall” which is now being replaced with “must”.

      • should NOT must

        “the firearm should be identified as required in 27 CFR 478.92”

        Don’t over look the following “required” while you focus to hard on the “should”.

        If you read it as a sentence and in context the answer is “required”

  5. I did some rudimentary machining on an old Bridgeport many years ago and I wouldn’t be too afraid to take this on. But I’m not a machinist and, above all, IANAL. I would need a clear understanding of what I may and may not do. Not that I don’t trust the internet, but …

  6. I believe the task of completing an 80% firearm is something we all have to **individually** research.Each state has their own laws and gidelines,and the Feds are so disorganized calling the BATFE will make things even more confusing.The fact that a homebuilt firearm has no serial number can pose problems for jurisdictions which outlaw posession by civilians of non-serial numbered weapons.Most such laws are intended to prevent crooks from scratching out factory serial number,but a clueless LEO who comes to know you have an AR15 or AK rifle sans serial number might not care about the intent of the law so much as the letter.This is a good article,but the subject of legality of such a weapon is too diffuse to be assumed by the author.

    • While it is a federal offense to remove, destroy or alter the manufacture’s required markings I have not heard of any state laws banning non-serialized lowers. There may well be, and it is always in your best interested to do your own research, after all even if it is 100% legal do not expect your local cop to know or understand that. Always C.Y.O.A.

  7. I’m genuinely stunned at how calmly all commenters regard and/or deal with the 80% rule. Never having heard of it before (for guns), I take issue given there’s not a 80% rule for quilts, or engine blocks or knives. Or anything else I can think of- Ok, belay that; there’s probably a 80% rule for nuclear warheads.

    More and more I’m becoming a unbending absolutist with regard to 2A issues.

    Seems to me the 80% rule is one more camels nose that wouldn’t be tolerated in other facets of our lives. Belay that too- There are far too many of these kinds of things which we DO tolerate in our daily lives.

    And finally, the flip mention of Katrina glosses over the fact the police did NOT go door to door saying, “We know you have a registered gun; give it up (for the duration of the emergency or not).” New Orleans is not that well organized from a database standpoint I’m sure- What they did do is say, “If you have guns give them up.”

    Both the Katrina scenarios and the 80% rule are all equally horrifying in my view. We, the public, should not put up with any of them.

      • I would guess its the shooting world’s tolerance of the Brady act and its evil stepsister, the National Firearm Tracing system /Etrace database operated by our pals at the BATFE.

        The only 100% way to own a gun that doesn’t eventually cross the federal radar screen is to make it yourself (via the 80% lower process) or to buy a law enforcement weapon off of a LEO private party without using an FFL.

      • Re-reading it, THIS is the sentence which set me off:

        “Federal law allows individuals to manufacture their own firearms.”

        Well. How special- Federal law allows me. But not without lots and lots of stipulations.

        This mornings reading included:

        – a little girl whose lunch was deemed nutritionally lacking and therefore replaced with chicken nuggets by school authorities.

        – a mom ARRESTED, possibly facing a year in jail and a $1,000 fine, for making her kid walk 4.5 miles to school after having been thrown off the school bus for multiple behavioral infractions

        -laws proscribing how old babysitters MUST be.

        And don’t even get me started on the TSA. I fly constantly.

        So I was appalled that commenters I respect on a blog I like were happily sharing the ins-and-outs of compliance minutiae. But I’m ok now- I’ve stepped back away from the ledge.

        This sums up my growing horror fairly succinctly:

        “What we’re getting from the White House on this conscience issue, it’s not an issue about contraception, it’s an issue that reveals a political philosophy the president is showing that basically treats our constitutional rights as if they were revocable privileges from our government, not inalienable rights from our creator,” he (Ryan) said on Meet the Press yesterday.

        And yes I know the problem is more than the current Administration.

        But I view all of this with concern-

        • Ahh, ok. Now I understand what you where saying. Short of building a bomb to hurt others, I agree that the feds should not have anything to do with what ever I decide to make for myself in my workshop. If only our country had some sort of list of inalienable rights…

    • Love your comment! LMAO. So the answer is we should not accept this? How does that work? Very magical. Saying that is like people have issues or have concerns. They no longer have a “problem”. There is a difference between should shall and required Should means recommended but not enforceable. Nothing further on this public forum. Who was prosecuted for the Katrina confiscation? LOL!

  8. Reviewing the regulations made my hair hurt.

    Anyway, it does seem that a homemade firearm can be transferred, and it seems that the transfer wouldn’t require a 4473 if the gun is held by the maker for a year.

    State laws can make the entire question moot, though, since each state can prohibit the whole process. Moreover: you can’t make what you can’t legally possess; a maker must have the appropriate state license(s), if any; and NFA firearms require the whole NFA rigmarole.

  9. Some examples of state laws which can jack up this process, picking from the worst two I could search on short notice:

    New York State law has an “Assault Weapons Ban” which outlaws frames that are based on the banned by name rifles, in addition to the popular prohibited features category.

    ****Any of the weapons, or functioning frames or receivers of such weapons, or copies or duplicates of such weapons, in any caliber, known as:

    Norinco, Mitchell, and Poly Technologies Avtomat Kalashnikovs (All Models)
    Action Arms Israeli Military Industries UZI and Galil
    Beretta Ar70 (SC-70)
    Colt AR-15
    Fabrique National FN/FAL, FN/LAR, and FNC
    SWD M-10, M-11, M-11/9, and M-12
    Steyr AUG
    INTRATEC TEC-9, TEC-DC9 and TEC-22
    revolving cylinder shotguns, such as (or similar to) the Street Sweeper and Striker

    As for defaced firearms, here’s New Yorks ambiguous take on the matter:

    **It is a crime to deface or alter the serial number or any other distinguishing number or identification mark on any handgun, rifle or shotgun, or to buy, receive, or dispose of a defaced firearm. Possession of any firearm that has been defaced creates a legal presumption that the possessor committed the offense.**

    -Million dollar question, does a homemade firearm qualify as defaced according to the law? I would say no, but the NYSP probably won’t see it that way.

    New Jersey specifically bans firearm manufacture unless said builder is state licensed.

    N.J.A.C. 13:54-4.2 Registration required
    No person shall manufacture or sell at wholesale any firearm or part of a firearm unless
    he or she has been registered by the Superintendent under the provisions of this chapter. This
    section shall not apply to a person who exclusively processes, or deals exclusively in, grips,
    stocks and other nonmetal parts of firearms.

    (a) Each manufacturer and/or wholesale dealer of firearms shall record the type, model, caliber
    or gauge, and serial number of each complete firearm, frame or receiver he manufactures or
    otherwise acquires, and the date of manufacture or acquisition of such firearm, frame or receiver.
    This information shall be recorded no later than the close of the next business day following the
    date of manufacture or acquisition.
    And if you do for some reason jump through the hoops to become a ‘registered manufacturer’ the lower still needs a serial number:

    N.J.A.C. 13:54-4.15 Identification of firearms required
    Each registered manufacturer of firearms shall legibly identify each firearm manufactured
    by engraving, casting, stamping, or otherwise conspicuously placing or causing to be engraved, cast,
    stamped or placed on the frame, receiver or barrel thereof in a manner not susceptible to being
    readily obliterated, altered, or removed, an individual serial number not duplicating any serial
    number placed on any other firearm manufactured and by engraving, casting, stamping, or otherwise
    conspicuously placing or causing to be engraved, cast, stamped or placed on the frame, receiver, or
    barrel thereof in a manner not susceptible to being readily obliterated, altered or removed, the
    model, if such designation has been made; the caliber or gauge; the name of the manufacturer and
    also, the city wherein the registered manufacturer maintains his place of business. A firearm frame,
    receiver or barrel which is not a component part of a complete firearm at the time it is sold, shipped
    or otherwise disposed of by a registered manufacturer shall be identified as required by this

    • Since I despise the whole of NJ (see I do not intend to contact them to check, but it would be interesting to see what they define as manufacture in this case. The ATF differentiates manufacturing for sale (FFL type 07) and for personal use. Either way I would recommend any NJ or NY residents to move, if that’s not possible then you should probably get a lawyer first before trying to finish a reciever.

  10. Might I suggest a nice Duracoat finish for the rifle in the picture? Aluminum doesn’t rust, but it looks better and lasts longer with a good surface treatment.

    • Yes, as long as you go through the ATF process to make one. Form 1 and so on. You would need to engrave it appropriately.

      Also, uppers are not registered because they aren’t firearms. Any AR lower that’s using a less than 16″ barrel must either be a pistol lower or a registered SBR.

  11. Could you give an idea of the overal cost savings on, say, and AR-15 or a 1911? Also, would it be a good idea for those of us who didn’t have shop class in high school to first take a course on machining? This sounds like a really cool project.

    • Ther aren’t really any cost savings since you can get lowers for 50-75$ now. The main reasons for 80% receivers are so you can put your own markings/logo/serial number/ safe-semi-auto markings and finish, and because it won’t have any paperwork associated with it so no fed Katrina raids.

      • Exactly what Matt said, but also add in those of us who like to make our own things. Something about that feeling of standing back and looking at something and saying I made that.

    • “would it be a good idea for those of us who didn’t have shop class in high school to first take a course on machining?”

      That would really depend on how you are doing it. There are jigs available for the AR that give you the location and depth to cut and you will end up with a “mil-spec” reciever. If you are wanting to make a perfect reciever then you would need to map out where the cuts are going to be and you would benefit from some training. There are a couple of forums about machining your own reciever, hit up Google and check them out. You would not be the first person to have that be your first machining project. Just remember to measure twice and cut once. You can always take more metal off, you cannot add it back.

  12. Not only will you NOT save money doing it yourself, it will cost you time. 80% are not to save money, it’s either for a fun project or to have an unregistered, undocumented (yet legal) firearm.

  13. Also, for those worried about sending the finished product to someone for engraving, you can send the 80% receiver and have it engraved before you mill it out, and the. Just finish it in duracoat or find a local who does anodizing, or even do it yourself, there are a lot of DIY metal finishing kits you can by and do it in your garage. Even Nickel-boron and the expensive coatings like that.

  14. If you’re going to go through the hassle of making your own firearm, there’s plenty of designs that would be easier to do from scratch (with you having to buy only a barrel) than any AR-based design.

    Start with falling blocks, for example.

  15. As far as making guns from scratch, the AR is a pretty complicated design that requires a lot of milling.

    For a much easier solution, I’d say one of those ‘receiver flats’ for a stamped-frame gun would probably work better. Back in the 80’s there were companies that sold receiver flats for the Ingram M10 (MAC-10) as well as the AK series. The flats were just that – flat sheets of metal cut into the appropriate shape and they either had the design printed on them or came with an overlay sheet you could put on top of it to show you where to bend and drill.

    I think receiver flats for the AK are still available. From that point, you just buy a ‘parts kit’ and assemble. Not sure how difficult/easy the assembly is, though, as I’ve never done it.

    • Probably more difficult than the AR, what with riveting etc. If you have the jigs, etc it probably is easier but a lot more expensive due to the high cost of the jigs needed. Just finished a polish underfolder and it took most of 3 months to get all I needed in place. I’d be able to knock one off now though in a day or less since I have accumulated all necessary equipment. It is not cost effective, though. And I didn’t do it for cost savings but to have the knowledge and fun.

  16. I am going to try my hand in the 80% thing. I remember going to the gun shop with little firearm restrictions. It was fun seeing the firearms that are on the ban list today.

  17. To the people who say you can’t save money by making guns with 80% receivers don’t know what their taking about. I’ve made two Ak74’s since the sandy hook shooting, total cost for both was about 900, and one was an ak105 clone, except a pinned and welded fake can to bring it to legal lenght, I’ve made two ar lowers for $300 including buffer tubes and stocks, I still need uppers but I found a place that builds them to your specs for $400-800 so I can do budget builds or go crazy. Either way its cheaper than buying an ar and customizing it, I haven’t done that because I just built a glock 22, that was the only build that cost the about the same as a store bought gun. Altogether it cost me $575. I could’ve done it cheaper but I was in a rush and didn’t wait for good deals on the slide and lower parts kit.

  18. 1. There is no “80% rule”. You either buy a firearm receiver or you buy a hunk of metal. The ATF has various criteria but no percentage-based regulations. 80% is a marketing term.

    2. As long as the home built firearm is not made with the intention to transfer it, you can later decide to transfer it. It is the ATF opinion that it would need your name and serial number at that point. Many think that this does not have basis in law but it is a good idea to do what the ATF says.

  19. If you build your own AR 15 and put your own mark on it…If you are stopped by the Police with it, how do you prove you built it yourself?

    • So you feel you must prove it is your property VS the government must prove it is NOT your property? Gun owners are so afraid of the Police and Government. Hey I understand. I wonder if the fact that our Government in it’s actions generates such fear in Americans IF they could be designated a Terrorist Organization? Law abiding yet so afraid to even make a mistake because you will be crucified by them.

  20. So it is a piece of metal bought without any serial number. So who knows WHO bought it and did the work? I have read about people buying them and then they are just are too busy to do the job. So they lay around for 3-5 years and the son or daughter says hey can I have this piece of metal and the family member does the drilling. Really seems completely not provable about who actually becomes the end user. Hell you could buy them and before the work is done barter them since they are only a “hunk of metal”. Seems like the end user is the person who has it at the end and says they did the work.

  21. “No willing it to your kids”

    Its not on record. How about NOT writing it down in your will? Most people don’t even have a will. Nobody would ever know if the deceased made the lower or if it was made by whoever inherited it.

    • I thought no one would ever point out this fact. Fear numbs the mind. A numb mind is easier to control. And control is what it’s all about. When enough people “break” the law, the law generally changes. Take pot laws. Or alcohol (prohibition) laws. When the people speak everyone listens.

  22. Sir, if you are still there. What if you are going to or from the range with home built weapon and stopped by LE? I’ve been told most LE personnel would go nuts if they found this weapon w/o serial number. Any thoughts or comments on this question?
    I live in TEXAS

  23. Whats the legalities of letting some one else shoot your non s/n gun? My local FFL guy wants to see my ar10 I just built and said “just don’t let me touch it, as soon as I touch it I need to put a serial number on it” I think he’s full of shit, the only laws I see are in regards to sale/transfer, not letting others use the gun.

  24. I’m a beginner but have read a lot about the 80% receiver solution. I’m wondering if anyone sells a kit and receiver for 12ga. shotguns?

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