Kramer Defense Files Patent for Bolt Heads for Cartridges Larger Than 6.8mm SPC, Wildcat World Reacts


Kramer Defense, the company that introduced the 6.8x45mm UCC cartridge based on the .378″/9.6mm diameter case head of 5.56mm, filed a patent on Aug 14, 2014 (approved Sept. 1, 2015) that has recently sent shockwaves through the 6.5 Grendel and cartridge wildcatting communities. The patent relates to bolts of larger diameter than the standard AR-15 bolt, coupled with cartridges of larger size and bore diameter. The most relevant section of the patent is below:

The invention claimed is:

1. A kit for modifying an M16 rifle, M4 carbine, or AR15 rifle or carbine, comprising:

a bolt having a maximum outside diameter (K in FIG. 3C) greater than that of a standard M16/M4 bolt (existing M16A1-A4 versions and M4 and M4A1 versions);

an ejector carried by the bolt;

a bolt extractor pivoted to the bolt and having a maximum width (F in FIG. 4D) greater than that of a standard M16/M4 bolt extractor (existing M16A1-A4 versions and M4 and M4A1 versions),


the bolt, the ejector, and the bolt extractor operable to:
transport a cartridge from a magazine to a barrel, and

eject a spent cartridge from the barrel,

a length of the cartridge is equal to or slightly less than 2.26 inches, and

the cartridge comprises:

a case having a case head diameter greater than 0.378 inch; and

a bullet having a diameter greater than or equal to 0.224 inch; and

a barrel extension configured to receive the bolt.

Because of these claims, many AR cartridge enthusiasts have become upset, with some even forming a Facebook group “Boycott Kramer Defense”, as the patent outlines a set of features that have long been the purview of wildcatters and others trying to push the capabilities of the AR-15 rifle. One example of this being Olympic Arms:


TFB asked Olympic Arms about this patent, and they said: “[Grendel / WSSM rifles] has been on the market since 2004, and first cataloged in 2005. Our Grendel bolts and extensions have been sold openly since at least 2010.”

Overreaching patents are nothing new; perhaps the most well-known example being the infamous “stick” patent of 1999, but a more recent and relevant patent of questionable scope being the Liberty Ammunition three-piece bullet patent that led to a court case with the US Army regarding their M855A1 round. Whether the Kramer Defense patent is an example of an invalid patent or not is uncertain, but certainly some of the features it covers are replete with examples of prior art.

On the Boycott Kramer Defense page, patent attorney Ben Langlotz explains a little more about the patent’s scope:


While this doesn’t necessarily mean Kramer’s patent is enforceable, it does exclude from the patent’s scope existing 6.5 Grendel rifles using bolts of standard outer diameter, as well as the Remington .30 RAR R-15, as it uses a different upper receiver forging.

Nathaniel F

Nathaniel is a history enthusiast and firearms hobbyist whose primary interest lies in military small arms technological developments beginning with the smokeless powder era. In addition to contributing to The Firearm Blog, he runs 196,800 Revolutions Per Minute, a blog devoted to modern small arms design and theory. He can be reached via email at


  • Gregory

    Who cares?

    • Mickey R

      Just a guess, but anyone who’s ever manufactured a non-standard AR bolt?

    • I care

    • tazman66gt

      Gregory, are you the new Lance?

      • Gregory

        Who is lance?

    • Don Ward

      Jesus Cares.

  • Mickey R

    I’m amazed that patent was issued. Should be easy to invalidate if Kramer ever tries to assert it. See, e.g. 35 USC 102(a)

    • tts

      Supposedly the patent office is critically underfunded and has been for quite a while and are swamped with patents with too few technical staff to understand them so they make mistakes frequently.

      I say supposedly because this is what I’ve been told by people who claim to know something on the subject but I have no good sources to back that up.

      • J Ad

        Half of patents don’t stand up in court.

        • tts

          I can believe that.

          The way patents are used frequently today is little more than a form of extortion. Friggin’ patent trolls + lobbyists have screwed the patent system into a terrible mess that is doing more harm than good at this point. Copyright has been awful for a long time too now.

          “This can go to court, and we’ll lose…but you’ll have to spend upwards of $500K in lawyer fees to make that happen. Oooor you can just settle for $50K.”

          • Thankfully, most patent disputes in the gun industry don’t end up in litigation. The vast majority of patent infringers will stop infringing when alerted, based on my years of experience in the industry.

          • J Ad

            Congress could have stopped non-producing entities, i.e. patent trolls, if they had amended the Fed. Civ. Pro. Rules in the AIA by requiring proof of production or some rules similar to the Federal Trade Commission requirements.

          • jcitizen

            I think if they could modernize the patent office and tweak the regulations; they could level the playing field a lot. I don’t like trolls either, but many of them have tipped the balance in favor of the US. It might be easier to negotiate a “use it or lose it’ approach in modifying the law. I agree they need to get together with US trade and business groups to hammer out what is fair, and implement it. Unfortunately the whole patent office needs overhauled too.

          • J Ad

            A Section 337 violation based on patent infringement can be found “only if an industry in the United States, relating to the articles protected by the patent . . . , exists or is in the process of being established.”30 This often is referred to as the domestic-industry requirement. The domestic-industry requirement consists of an economic prong, requiring certain activities, and a technical prong, requiring that those activities relate to the asserted patent.31 The economic activities can be demonstrated by significant investment in plant and equipment, significant employment of labor or capital, or substantial investment in exploitation of the patent, including engineering, research and development, or licensing.

  • ostiariusalpha

    Heh, more like Cosmo Kramer Defense, ’cause this patent filing is a joke.

    • El Duderino

      This would have been the coolest episode of Seinfeld. Well…maybe after the Soup Nazi one.

  • allannon

    Well, this is right up there with the infamous “something people do all the time, but on a computer” patents that are plaguing the tech industry.

    I wonder if the EFF would name this the Stupid Patent of the Month. “AR-15 bolt…but BIGGER!”

    • JK

      Wonder if I can file a patent to cover downsized 45ACP rounds, and get royalties from everyone manufacturing 380 and 32 ACP?

  • This is a problem with the Gun Industry… too much fuqqery. Like Robinson Arm’s patent filing. Everyone in the Industry should turn their backs on Kramer for this BS. Including the Gun Rags and Blogs and Dealers and Distributors. This sort of BS is unacceptable.

    • jcitizen

      It is a problem across the entire industry in the US. This is the one place the government could help our economy, by giving us a modern road to innovation, and they are falling flat on their face, in my opinion.

    • For every one of those dubious patents (many of which turn out to be legitimate or misunderstood anyway) there are hundreds or maybe thousands of good patents that do their job.

  • It’s a challenge in every industry: granting patents that are deserved, and not granting ones that aren’t. But realistically, we have plenty of legal options to deal with “bad” patents. Patent examiners are ordinary humans (even government employees!) who are imperfect, and face plenty of limitations on them by the system they work in. The examiners in the firearms group are the best I’ve worked with – smart, cooperative, and sensible.

    The telling factor is that Kramer has other patents pending, because they probably realize that these claims as granted will probably never hold up. But I haven’t given it a full analysis, so that’s not my final opinion.

    • Thanks for commenting, Ben! Please feel free to email me at, I’d love to hear what you think of the M855A1/Liberty Ammunition case.

    • J Ad

      Some forms of reexamination is certainly in order given the prior art. For example, Olympic should request an inter partes reexamination as they had products on the market prior to the patent application.

      • True. Any party facing the threat of a lawsuit has these tools available to counterattack the patent, and the patent owner knows this.

        • jcitizen

          US Industry and innovators need some form of permanence to the system, so all these patent attorneys don’t soak up all the money that should be going to the innovators. I see it all in a very frustrating light, as I have worked for such people and have seen their struggles.

          • I don’t understand what you mean by “permanence”. Legal fees are expensive, but it’s expensive to properly develop a piece of intellectual property to generate a profitable business, just as it’s expensive to develop a piece of real estate to develop, say, a shopping mall.

            The key thing inventors need is an honest appraisal at an early stage (before they’ve spent a penny) on the costs and options for patent protection. The other thing they need is a patent attorney who will coach them on how to preserve their rights, while minimizing and deferring legal fees as long as possible.

          • jcitizen

            I personally think an attorney could be kept out of the entire process if it were done like it used to be when the office started – when the rights of the innovator were the ones being protected. Once this patent is issued, the innovator should not have to have some pop up challenger to ruin their lives afterward. I really believe that a modernization of the patent office and and overhaul of patent law and the office itself is in order here. I’m even on the side of the trolls to a limit. There should be a use it or lose it mentality, and even then, an arbitration framework so that both parties can meet in the middle. In the case of the trolls, I think they should be forced into a partnership with the entity that actually had the knowledge and guts to build the factory or other infrastructure and organization to make the product happen, but not run over the originator of the idea as well.

            In the 1880s it was the patent office that protected all parties and did most of the part of enforcement – lawyers only came in when people like Westinghouse wanted to take on Tesla for ideas that he originated, but was under employment by him to give up his rights. Even John Browning had the sense to keep some of his ideas to himself and not give them up to Winchester, Smith and Wesson, and Colt. He could stand up to the giants when he was right, and the big manufactures were protected when they were right. That is how it ought to work.

          • It sounds like your concerns are the examination and granting of rights but enforcement and arbitration of disputes. Are you sure you really want to expand the PTO’s role so vastly? I’d say it’s better to help them do their current limited job well.

            I can’t be sure of the history, but my sense of the past system was more of a registration process, where the applications were accepted for whatever they showed, and it was up to the owner, courts, and the accused to resolve what patent rights were enforceable.

            A court then answers the question: “What can be claimed here?”

            Our current system gives the patent applicant much more benefit by creating a powerful presumption of validity, and a clearer delineation of scope.

          • jcitizen

            I’ll pick just one of the innovators I know. He spent considerable time and money getting the patent, then spent almost all his time defending the thing afterward, to the determent of his business. In this electronic age, I feel things could be greatly simplified and enforced. A developer should not have to sacrifice his life just to get a product protected; so yes, I feel an enforcement mechanism should be put into the equation. The MPAA got theirs!! Since when is Hollywood and entertainers rights more important than other inventors? Seems like all they have to do is squawk, and all hell breaks loose! My interpretation could well be way off, but that is how I feel on the subject.

    • J Ad

      The priority date is February 2008, but the 6.5 Grendel came out in the ar15 in 2003. It seems that there should be enough printed publications to prove a substantial issue of patentability and likelihood of success on one of the claims if someone wants to challenge this patent.

    • jcitizen

      The patent office itself is one of the greatest problems in US innovation, it rewards the corporations and runs over the little guy – totally antithetical for truth, justice, and the American way. We badly need to overhaul the US patent office BIG TIME! Hell – they just barely computerized many of their records, and I read that was a disaster too! I’m sure we need to overhaul patent law to keep frivolous patents out of the system too – I refuse to believe this can’t be accomplished. We did just fine for over 100 years, and “were” the shining light of the world until recent times.

      • I agree that the PTO could use some improvements. It’s government agency. But in the Firearms group they have some smart and talented people who do a great job under challenging circumstances. In my 25+ years of practice, I have represented Fortune 100 companies as well as individuals and start-ups, and have never once detected any bias in favor of the big boys. My “little guy” clients get some very careful attention by the firearms examiners – maybe they know I don’t file frivolous patents, but I doubt my reputation has that much of an effect.

        I’m not sure exactly what kind of overhaul you would propose. I’d support a mandate to keep all fees in the PTO, and not steal them for the general fund (I call that an “innovation tax.”) I’m unsure of what was done well for 100 years, and what changed more recently. As far as Ive seen since 1990, the system has gotten better and better and my small clients have a better prospect at getting meaningful protection in a shorter time than ever.

        The undeniable truth is that its expensive to properly protect an invention, and people with money will have an advantage over poor inventors.

        I’m also unsure how you would keep out “frivolous patents.” There will always be some patentable inventions that are unjustly rejected, and some others that are improperly granted. But there are safeguards (like appeals, post-grant review, and litigation) to correct those errors. Would you add a pre-examination step to determine if an invention was “frivolous”? What legal standard would you apply?

        I’m genuinely interested in hearing your reform ideas. Just know that I hold no sway, so persuading me won’t help your cause. 😉

        • jcitizen

          You have made good points with your optimistic view, I realize you have great experience, but that doesn’t mean a lay person can’t parse the situation as well. I addressed some of my ideas on reform in a later answer to you below. I’d like to add that upgrading the computer system at the patent office would help, but they need even more ability, such as web surveillance to detect copyright infringement, and maybe even an artificial intelligence system to analyze circuits and mechanical diagrams for infringements and/or prior knowledge. I would even agree that perhaps bids for contractors to provide intelligent services like this be presented to the OMB to see what is the most efficient way of reaching these goals.

          Some day they may need an AI machine like IBM’s WATSON, much like the 1880s Census Bureau needed the Babbage Engine to do the work needed. Before you dismiss such musings, look at how the MPAA has weaved DRM into our everyday life with all our devices to prevent violations on protected content – the patent office could use similar or other technology to help achieve very similar goals.

  • John Bear Ross

    They suck.
    Hopefully they have their ass handed to them in court, and have to pay attorneys fees as well.


  • nova3930

    If the US patent system was sane this would be tossed on prior art grounds.

    • It is sane, and while a bad patent may issue, there are plenty of ways it can be invalidated.

      • Marc

        That’s not sane.

  • Nerf McDermitt

    Previous existing art is going to sink this one. The patent office is really something else these days.

  • JumpIf NotZero

    A lot of of people that don’t understand patents all around here.

    Filing and receiving a patent means absolutely nothing.

    A patent does not give the owner “a right” to make something or a promise they will exclusivity to anything.

    All it does is form the basis for a lawsuit. That’s all. All this patent means is that Kramer’s lasers would have a starting place for defending themselves in a lawsuit. Not that they would win. Not that they would stop anyone from making a product that violated the claims, although changing a claim is trivially easy.

    Bla bla bla… Let’s turn the panic down a little bit.

    • Thom S

      As someone who works in IP law, I’m amazed at both your level of wrongness and the assurance with which you go about being the same.

      • Thom, I’m always recruiting for IP staff who have knowledge of firearms technology. Contact me via my website if you’d like to get acquainted.

        • Thom S


          Thank you for the kind offer. Unfortunately, I am probably a bit far away to take you up on it.

          If you ever need any assistance regarding South African IP law, I would be happy to help.

        • No job advertising allowed——

  • Vitor Roma

    I don’t believe in any kind of patents, it’s the state enforcing a monopoly over an idea/concept, creating scarcity. But I would be glad if patents got their time reduced. The current 25 years time is absurd. In a world of rapid innovation, 5 years should be “fair”.

    • You really don’t understand what patents are, do you?

      • Vitor Roma

        I do, it is a granted monopolistical privilege in the production of something that has certains concepts. It is the right to violate physical, tangible property of other people who violated a very ambiguous concept of “intellectual property”.

        The funny thing it doesn’t even foster innovation as many people think. Since the patented product is composed of concepts, materials and designs created by other people. Innovation happens when ideas breed instead of remaining isolated. There is nothing wrong with copying some design and concept, specially that everyone has a slightly different view and execution of the concepts that allows gradual and constant innovation. See how guns evolve, imagine if someone had the monopoly in the rotating bolt or certain gas system, how we would have a much poorer selection of designs.

        Patents ends up being so random that even their validity is pure ad hoc. Why 25 years? Why not 20 or 30 or the life time of the inventor? What kind of VALID property right has some random limit?

        Also you don’t steal an idea, you copy it. Copying is not stealing, the concept can live and reproduce in millions of minds. You don’t have the concept erased out of your mind because I got it to my mind.

        So, to sum up things. Patents are basically the idea of telling the state that you think the state should harass anyone who you believe is copying (or close to copying) an idea or concept that you had. It alsos protects the “original thinker” from compeition coming from other people that can apply the concept and idea in better fashion. A novel idea ain’t worthy a lot if it can’t be converted in good products.

        • Tassiebush

          I 2/3 agree and 1/3 disagree. I think there are some very compelling arguments against upholding patents. It’s literally life and death in many ways. The only thing against it is perhaps the example of something that costs a lot of money to invent but which can be readily copied. Still perhaps another system could compensate and reward such effort. Someone smarter than me can solve that one.
          I am sure someone will shortly point out a significant flaw in what I have just written lol!

          • jcitizen

            I’d say you’ve parsed it pretty well!

        • Curmudgeon


          So I guess you think that what happened to Eli Whitney following his patent of the cotton gin was just peachy, eh?

          Communism has quite stunningly proven (to those not blinded by idealistic and fantasy orthodoxy) what happens to innovation and production when people are denied the benefits of their work and their inventiveness.

          Patent law embodies some tricky public policy balancing of competing interests. For the most part, the current 20-year balance seems to work well enough for unique and useful inventions. A line must be drawn somewhere, and the lifetime of the inventor would cheat his or her heirs if hit by a gravel truck a week after the patent was granted.

          Or do you also want the Guv’mint to take everything of value from every citizen after they die? Leaving things for only your children or chosen charities or whatever is just another form of monopoly that should be eliminated so more people benefit from well-funded government giveaways, right?

    • Thom S

      You and Jumpifnotzero should start a club or something.

    • The Founders knew that granting limited rights to inventors would help make the US the most powerful economy in the world. The current system grants rights that expire 20 years after the first filing.

      • Vitor Roma

        Patent lawyer, I see you have the generic cookie cutter responses ready. What do you think of your colleague Stephan Kinsella and his book Against Intellectual Property?

        • I’m sorry that my correcting your legal error came off as “cookie cutter.” It was custom-written just for your error.

          Patents are for some, and not for others. They should be viewed as a business investment question. Patents (and copyright) reflect the only use of the word “right” (or “rights”) in the original U.S. Constitution. I’m comfortable supporting a system, however imperfect, that has made our nation the most innovative in the history of humanity.

          I’m not going to debate a book you cite, but if you care to make a point, I’d welcome hearing it.

    • jcitizen

      Without patent law our economy would quickly become like China, where only influence can get ahead, and anyone with enough push can take away the ideas of the laboratories and rob the intellectual property rights of the individual. This would kill innovation here, and has already in China. The ability of an organization or individual to come up in the world with innovation is an American staple. It is what made us great – the only problem is what you see right here in this discussion – the system need tweaking to end this abuse. However we must be careful to protect the people who sacrifice their whole life for an idea and a dream to make something of their labors.

  • iksnilol

    Nathaniel F. was actually so upset he didn’t come up with funny tags.


    • jcitizen

      The whole subject is a burr under my saddle! >:(

  • Tassiebush

    It seems like they are just claiming bigger is somehow an innovation

  • DIR911911 .

    with that much vagueness it kind of sounds like they just put a patent on my dpms 308

  • Vitor Roma

    I invite anyone to think about the AK and AR. Their parts were not innovating. Piston, rotating bolt, springs, gas tube, all done before. It’s how they were executed that made them incredible platforms, it is how Stoner and Kalashnivkov and their teams took ideas from other people and used those ideas in a smart way.

    • ostiariusalpha

      Nobody had ever thought of the internal piston and its in-line cycling push before Eugene Stoner came up with it. It may seem simple enough after the fact, but to come up with the idea took a sophisticated understanding of firearm operation and design.

      • Vitor Roma

        Damn, so no engine had some inline mechanism then? Stoner is the creator of the straight line? The AK mechanism works in a straight line, the stock to receiver geometry that is not straight. Now granting patents in a geometrical shape is a good example of patent trolling, like Apple wanted to have exclusivity in “rectangles with rounded edges”.

        • ostiariusalpha

          Uh… were you trying to sound derptastically clueless, Vitor? Well, you succeeded masterfully. Firstly, no, there isn’t an engine that operates like AR internal piston, not on any vehicle. Secondly, the piston on an AK is offset from the boreline of the gun, and like all firearms with offset cycling impulses (the Garand, MAS-49, FAL, vz. 58, SCAR, and all the AR-18 derived short-stroke designs), it has to be designed around a certain degree of carrier tilt. Also, having a reciprocating mass offset from the boreline creates an inherent muzzle flip that has to be dealt with. The AR internal piston eliminates both of those issues by keeping the cycling impulse in the boreline, the fact that the AR also has its stock in line is just icing on the cake.

  • John Daniels

    More examples of why intellectual property is a nonsense concept.

  • SouthernGrind

    I tried to join the Boycott Kramer Defense Group on FB and received a message from Johnathan Whitney. He informed me that he blocked my request and also sent a copy of my old business’s web page to Kramer Defense so they could sue me for selling Young Manufacturing’s H Wall bolt back when they manufactured those. How is it a man on a Boycott Kramer Defense Group page is turning in business’s to Kramer Defense for them to sue?

  • jcitizen

    I think if you two guys got into a room and thought it out, you would both agree that some changes could be made that would benefit every one who deserves it, and not the ones who don’t deserve it – and America could go on being the great country it is. I agree that something needs to change, but just don’t throw out the baby with the bath water.

    • Vitor Roma

      Reduce to 7 years the duration, demand that every patent will only be valid if applied to to an actual product in the market, don’t accept any geometrical shape or programming instruction as valid patents to avoid vague patent trolling and I will be glad.