Interesting New Pistol Design

Timothy Lindsay (USA) and Renaud Kerbrat (Switzerland) are listed as the inventors on the recently published patent application #20100077643. The patent describes a new pistol recoil mechanism that is similar to is the mechanism used by the TDI KRISS.

Like the TDI KRISS, the bolt recoils downwards to reduce perceived recoil and muzzle rise.

Prototype .45 Pistol
Steps showing the bolt recoil
The inventors envisage some pretty wacky rifle and carbine designs.

UPDATE: Some astute commenters pointed out that Renaud Kerbrat is credited with the KRISS design. So this could be said to be the KRISS patent. What is interesting is how long they took to submit a patent application to the USTPO.

You can read the full patent after the jump …


Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • viper5552

    well, the sights/optic mounts look… nonexistent but design wise i say go for it! the firearm market really could use a breath of fresh air

  • Patrick

    Besides the fact that it looks like it would be impossible to aim having a grip similar to a sawzall it is an interesting design although quite complex. I am also curious what the battery is for in Fig 21 & 22 on pg 15. I do not desire anything battery pwered on my firearms except lasers and lights.

    Also the last item on pg 46 Identifies a Bolt and Slider assembly. I wonder the designers true firearm kowlege.

    • Patrick, I also wondered about the battery when I first saw it. It is just there to illustrate that a battery could be stored in the grip.

  • SpudGun

    While I’m all for innovation, the KRISS style systems seem to be a step backwards in terms of practicality.

    A typical KRISS weighs over 5 lbs, so there will be a reduction in recoil based on sheer mass alone.

    This appears to be a design solution looking for a purpose.

  • rubbershotgun

    while i welcome all new firearms designs, i can not help but wonder about the designers experience with firearms. the illustrations suggest that the designer has sound knowledge of how the mechanical components of a firearm should work. but everything else gives the impression that he has never seen a firearm, only read about it in books.

    best of luck to him with his new patent, he is going to need it when he gets sued into bankruptcy by kriss-tdi

  • Redchrome

    I’ve seen at least one of those prototype guns a while ago, in a Small Arms Review article about the TDI Kriss Vector SMG. Might even have seen them on Magpul’s website a couple years ago, since they did some of the initial development on the Kriss (or so they claimed).

  • Okki

    You rack a round by pulling down on a ring at the bottom of the gun? It would seem to me that you decrease the ability to get on target while employing such a method of racking.

    It would also seem that the distance between optics and bore is relatively large in all configurations as shown. this will make it increasingly harder to zero/keep accurate at varying distances.

    Lastly, the trigger seems to have to be pulled “up” instead of squeezed “back”. in order to do that it would appear you need to twist your hand forward in order to move your fingers to be “under” your hand. that does not make for a very secure and stable shooting position.

    To me this almost looks like a “placeholder” patent. Someone came up with a tilting bolt design that doesn’t violate the KRISS design, but if someone else wants to employ a similar design they now stand a chance of suing for royalties, or sell the design.

    it’s definitely interesting to see people trying to innovate in the firearms industry though.


  • Sian

    I congratulate them for thinking outside the box. Recoiling into the line of the forearm would make it very mild and controllable.
    But how do you sight it, and how is the front-heaviness dealt with?

  • Amuse Bouche

    Steve, Renaud Kerbrat IS one of the inventors of the KRISS system, and the top picture is identical to their prototype featured in several videos, as for the first cut-away in the patent application.

  • Mark

    Kerbrat is the inventor of the Kriss-Super-V-System. What you describe as “Prototype .45 Pistol” is afaik an early Kriss prototype.

    Read the whole story here:

  • Mark
  • Anton

    Wooh, aiming devices would look like this:

  • That looks quite a bit like the prototype KRISS… at least to me.

  • Slim934

    And let the patent battle begin!

  • John

    I’m not a patent lawyer, but wouldn’t this patent infringe on the KRISS patents. Or are patents that pointless these days.

  • Crabula

    So I’m confused. Did someone steal the design from someone else, or are these the same guys that developed the KRISS. I kinda want some clarification on that.

    As far as I can tell, I am looking at a KRISS with the stock removed. The illustrations on the second page, as well as figure 27-29 in the blogpost show a method of operation that seems to be identical to the animation on the KRISS website.

    There, go to that link and scroll to the bottom of the page. The geometry of the mechanism, as well as the motion that occurrs appears to be identical.

  • Andrew

    I’m pretty sure that’s the prototype design for the Kriss, prior to Magpul’s involvement. I remember seeing a picture on Magpul’s website that looks exactly like that.

  • Jeffy Poo

    Kind of reminds me of the pistols from the original Dune movie.

  • Jesse

    The design seems interesting. By having the barrel more in line with your arm it should reduce muzzle flip and allow you to return to target quicker. By separating the magazine from the grip you can have a grip that more easily fits all sized hands like a revolver but still have more ammo on hand. you remove the compact nature of the hand gun so it’s clearly not good for concealing but for a compact high capacity home defense weapon it would be ideal. Just throw a rail on top of the grip and put a reddot on it and you’d be set.

  • Cogent

    These would look great in the next installment of the Alien series.

  • Crapsworth

    This thing looks more like it would be more at home driving nails into concrete than firing bullets.

  • Dave

    I think it looks similar enough to the KRISS that their lawyers might come calling.

    Also looks like someone’s been playing too much HALO. 🙂

  • Don

    Well that’s a bit weird.

    Maybe this sound pessimistic or whatever but I’m a bit skeptical of these radically different mechanical designs of long-established technologies. I don’t consider this to be a pessimistic thought, just a practical one.

    What I see happen with successful and enduring new designs is that they typically follow the development of a new construction materials, and then consist of incremental advances on the old design which leverage the new material’s positive attributes and compensate for it’s weaknesses.

    Like what high strength plastics did to firearm design. Plastic frame pistols didn’t jump on the scene being radically different designs from their precursors. It started slow, stocks, grips, frame components, etc. It doesn’t seem like there were any huge jumps in mechanical design there.

    The other thing that triggers a divergent design is a new manufacturing method or the maturation of a previously unsuitable method, for example Ruger’s casting method is cheaper/easier than the forging method, but it took a while for casting to be comparable in strength to forging, and then the Ruger revolver design evolved based on the attributes of the casting method.

    Bow’s (archery) are kind of similar. You see the switch from wooden risers fiberglass composites, which were strong enough to accommodate a simple cam system (which already existed in other applications). The cam technology had a higher potential for powerful limbs so they switch to metal, and then for manufacturing cost reasons they stuck with castable metals, the strength of which limited limb lengths and cam geometries and when CNC machining technology went down in cost machined risers came on the scene which raised the bar on the limb and cam geometries again… so on and so forth…

    Same boats, buildings, vehicles, tools, same with everything.

    Point is you see a very logical natural progression in the design based on the availability of new materials and manufacturing technologies. I think that design is done that way for these long-established technologies because that way you leverage millions of man-hours of engineering already put into the technology. You just can’t expect to compete with that kind of a design effort working from scratch.


  • Maigo

    way over complicated

  • Bill Lester

    Imagine trying to carry one IWB! 😮

  • If the prototype is only to demonstrate the device will work for the patent, maybe the design makes sense (clearly the trigger could be modified into something more practical). If it will reduce recoil significantly, perhaps it has an application in machine or other larger guns but not a replacement for the M-16/M-4 or similar – seems like it’d be too heavy. I searched for video of the device but no joy.

  • wlitten512

    A design like this and the KRISS rifle seem like they lend themselves well to a bullpup design. I can’t wait till some one tries it. Imagine a .45 bullpup SMG.

  • Airrider

    Unless, of course, they figure out some way to lighten the system. Although you have a point: compared to more basic recoil reduction methods it’s a bit overengineered.

  • Guys, thanks for the info.

    I recall that another gun, from way back, used a similar recoil system? Can anyone remember what gun it was?

    I have “Luger clone” stuck in my mind … did a Luger style sub machine gun even use a downward style recoil mechanism? To many guns in my head.

  • Dave

    I call bullshit on the entire kriss vectoring design. There is a rearward force upon the bullet casing that pushes the firearm directly back along the bore axis while it is in battery, and a slight torque on the barrel as the rifling exchanges angular momentum with the bullet. The torque is light compared to the rearward force, so let’s ignore it. That rearward force causes muzzle flip on most firearms because the center of gravity is below the axis, and so you have a torque moment that makes the muzzle rise. As far as I can tell, the main characteristic of the kriss that mitigates flip is the low, low bore axis which is likely near to bisecting the center of gravity of the whole gun. This torque vector thing works by exchanging momentum with that god awful slanted sliding bolt carrier so that some of the ‘kick’ is directed in line with the recoil spring. The thing is, that momentum is coming right back in the opposite direction As fast as the gun recoils. I don’t have a sketchpad near me, but my instincts on momentum tell me that the system PERHAPS delays the flip, but, like the twisting cat that always lands on its feet, the system can’t violate the laws of angular momentum. Stupid gun with a low bore axis jazzed up as a Jesus weapon.

  • vtb

    Well… it’s strange to me why not to hide recoil mechanism inside the pistol handle and make some kind of ‘target pistol’ look-like Mauser “Broomhandle”…

    PS. to reduce recoil without muzzlebrake or to make gun move after recoil not up-left but to neutral-left or down-left (in case it ejects cases to the right) you can just move “bore-centerline” of stock upper in relation to bore-centerline of barrel.

  • bullzebub

    steve : not really a similar gun but a similar idea:
    witch is in my opinion a better solution. smaller package, simpler design and cheaper to produce the AEK 971 has a similar idea too… witch is (as the jatimatic) superior in my opinion.

    some negative points about the KRISS and the jatimatic is that they are sub machine guns and those are losing grounds to carbines. also there is not really anything for the civilian market since the effect is mostly for FA firing…

    fun designs though 🙂

    • bullzebub, thanks for the links.

  • bullzebub

    vtb: you cant do that. The downward force has to be in front of the pivot point (the wrist) or after (but then the force has to be directed upward).
    what this system actually do isnt reduce the amount of recoil force but helps the platform stay level by eliminating the “twisting” action.
    you could do that just as easily by placing the barrel in line with the forearm. it would require more adjustment though.

  • snmp

    Renaud Kerbrat is French and Gamma KDG Systems SA ( (Gamma KDG Systems AG or Gamma KDG Systems Ltd) is Swiss compagny who have right to sale Kriss in Europe

    • snmp, thanks for the info.

  • Steve,

    There was a design called the “Piranha” where a Luger-like toggle bent down inside the pistol-grip. The frame was hinged like the Madsen SMG for field stripping.

    • Daniel, ah, thanks!

  • A. Shooter

    I can assure you that the patent application was submitted a long time ago. There is no way the holder of the patent would put prototypes and serial manufactured finished items out into commerce without knowing they were protected on the intellectual property. Notice on the first page it states that this is a “continuation” of applications dating back to 2003? You would want to pull those as well to see more. This is likely a refinement to their application.

  • The Piranha was designed by Walter E. Perrine. You can find his patents online.

  • CY


  • Redchrome

    Thanks for the information about the piranha, Daniel. I always wondered what happened to it. The example I saw in Guns & Ammo about 1990 looked really interesting. I don’t remember the one I saw being a toggle-locked design tho; I remember one wherein there was a wedge-shaped rotating weight, pivoted around the narrow end of the wedge, much like the crankshaft counterweight on a single-cylinder motorcycle engine. The back end of the bolt pressed against this rotating weight, which was sprung by a spring on a guide rod going down into the grip. So as the bolt went back, it would rotate this weight, which would both delay opening and provide a countermass to redirect the force of muzzle climb.

    Seemed like a marvelously good idea. The ‘Super V’ system as embodied in the Kriss works much the same way, except that the weight slides on an inclined plane instead of rotating.

  • I’m with Dave on this one. There’s a little rule in physics called Newton’s Third Law which can be summarised as “every action generates an equal and opposite reaction”. So if the bullet and propellant gases go forwards, the gun goes backwards. It really doesn’t matter much in which direction the bolt moves. As others have said, if the gun doesn’t recoil much it’s because it’s heavy. If the muzzle doesn’t flip it’s because of the low barrel axis relative to the pistol grip.

    It seems to me to be a lot of effort to make what is basically an awkward and overweight gun.

  • Hercules Perrine

    Walter Perrine died last year. His nine millimeter shot like a 22. It had nothing to do with the weight of the pistol. I also shot a fully auto version, no recoil as well. He made frames out of ss and aluminum. He filed over 21 patents in his lifetime, and was also the inventor of the arm blaster, which weider never paid him the millions owed him. Inventors routinely get cheated out of their royalties.

  • Tim Mullins

    A bit of a late reply on this thread, but did anybody ever figure out that this is the KRISS? Or that the battery in the handle is for a laser sight system? You can’t try to interpret the drawings on a patent literally, because it just doesn’t work out that way (usually). The phrase “prior art” is laughable because most inventors don’t appear to be very good at drawing.

  • RP

    Patent drawings are done by trained artists, not inventors themselves. The drawings are intended to provide just enough information to meet USPTO requirements to secure the patent without giving any more information than absolutely necessary. This is why they appear so basic. “Prior art” is a specific legal term meaning the state of the art in a field – that is, if an invention or part of an invention is prior art, already available to the public generally, it cannot be patented. It applies to the patent applicant’s claims of originality.

  • Tim Mullins

    Yes, that’s the definition of prior art. But I did not know about actual artists doing the drawing. I just picked up on the fact that everybody seemed to be interpreting the drawings on this page literally, instead of looking at them like an electrical schematic or similar. Interpreted on a literal basis, then yes, this weapon would be a bit clumsy at best.

    My point is just this: you have to see the manufactured product before passing judgment on a product, because the “art” isn’t going to do anything more than clarify the concept. When it does that. There is more than one reason patents are infringed after all.