Inkunzi PAW aka Neopup – 20mm Direct-Fire Grenade Launcher

 

The Inkunzi PAW (Personal Assault Weapon) is a 20mm shoulder fired semiautomatic grenade launcher designed by Tony Neophytou (and previously known as the Neopup). It is a creative and very interesting weapon system, both from a mechanical perspective and also from a question of practical application.

The PAW has a 6-round detachable rotary magazine, and an effective range of 1000m for area targets and 600m for point targets. Its purpose is to give the individual soldier an explosive area-effect weapon that fires like a rifle. To this end, the ammunition has been developed to give a muzzle velocity of 1000fps (310m/s), giving it a far flatter trajectory and shorter flight time than a 40mm grenade, either low pressure or high. It allows rapid repeat shots, rapid reloading, and easy target transition. The high muzzle velocity (for a grenade launcher) makes range estimation and engagement of moving targets much simpler than with the rainbow-like trajectory of 40mm systems. For specialized modern applications like guarding against one or more vehicle suicide bombs, fast-moving pirate skiffs, it seems extremely compelling. That utility extends to typical targets as well, like light armored vehicles, buildings, gun emplacements, and even something as simply as a patch of brush with an enemy hiding within somewhere. Typical small arms fire requires a substantial expenditure of ammunition for targets like those, while an explosive 20mm projectile can neutralize them in one or two rounds, without the need for a direct hit. The lethal radius of a 20mm HEI shell is between 6 and 18 feet (2m – 6m) depending on who you ask. That’s a significant margin of error.

Mechanically, the PAW is a simple system to disassemble, and it uses a quite clever inertial locking system which is clean and reliable. The unique layout with the grip on the right side is done to accommodate the hydraulic recoil system, which allows the action to slide back into the stock assembly on each shot. This absorbs much of the recoil and spreads its effect out on the shooter, making it not unpleasant to shoot. An easy stowage feature allows the gun to be locked in its compressed configuration, shortening it for transit and also offering a way for the gun to be carried with a round chambered and ready to use, but with the trigger safely disconnected to prevent accidental firing for troops in armored vehicles or helicopters.

Compared to the American XM-25, the PAW strips away the overcomplications of laser designation and complex projectile fusing, which are arguably not really necessary anyway. It offers a simple and effective system, with tremendous firepower as well as suppression capability (nothing says go away quite like rapid fire explosives). It does this with a larger magazine and more compact and lighter weight design, no less.

It is rare to find a truly unique and innovative firearm these days, but that is exactly what Tony Neophytou has done here. The design is elegant in its simplicity, and well refined. It truly offers a unique set of capabilities – while it has been purchased in limited numbers by several smaller militaries, I hope to see it given serious consideration by some first-tier forces, as I think it has tremendous potential.

52 Comments

  1. “Say hello to my little friend!” I wonder if this would be great for clearing out thick bushes and trees. I have heard of camouflage experts so good that they could hide in a tree right above a busy bike lane for months yet not be seen…

  2. Now, this is a unique system with realistic application. Tony N. is talented designer who proved himself with previous designs including dual feed Neopup shotgun. Being able to see it in real shooting demonstration and its internals is much appreciated as this is a crown jewel in so far ‘techno’ category of FW.

    • I expect it’s for a PEQ-15 or similar illuminator/laser sight, since there’s no provision to mount one on the handguard like an M4.

      My first thought was a secondary optic such as a red-dot in conjunction with a magnified main optic, but as Ian says you wouldn’t want any normal magnified optic due to the telescoping recoil system, and I’m not sure of the ergonomic feasibility of rotating this 45 degrees to use the secondary optic — shouldering a 5.56 rifle at crazy angles works because of the minimal recoil, but doing that with the neopup sounds painful.

      • That makes sense. a night vision device along with a primary sight would allow binocular vision allowing easier and more accurate use at night.

  3. “The lethal radius of a 20mm HEI shell is between 6 and 18 feet (2m – 6m) depending on who you ask. That’s a significant margin of error.”
    Surely such ammunition it has advantages, but question if costs of its introductions are outweighed by advantages? 40 mm grenade launcher seems to have firm ground, with new patterns created, including selective-fire ones like for example HYDRA by Rheinmetall Waffen:
    https://www.thefirearmblog.com/blog/2016/01/22/shot-2016-milkors-hydra-handheld-automatic-grenade-launcher/

  4. 20mm? High Explosive filler? Impact fuze?
    This reminded me about Minengeschoss as used by Luftwaffe during World War II.
    Looking at 4th image from top here:
    https://modernfirearms.net/en/grenade-launchers/south-africa-grenade-launchers/paw-20-eng/
    it also similar due to case used, as they are straight-walled (ok, nearly straight in case of 20×80 RB), though obviously in 20×80 RB it is longer:
    https://naboje.org/node/8533
    (this cartridge was used in MG FF, other noticeable difference is that 20×80 RB has rebated rim, which is due to how MG FF works)

    • This has practical application only with impact fuse warhead filled with HE. Although, another possibility may exist if subcaliber sabot guided penetrator was used. That may do well against lightly armored vehicles.

      • The most obvious application, as Ian stated, is stopping a “civilian” vehicle you don’t wan to get too close to, due to the likely cargo being an IED. In fact the SAPHEI round would probably detonate said cargo with one or two hits other than on the engine.

        On the other hand, if you want to stop the vehicle but leave its contents (semi-sentient or otherwise) more or less intact, one or two SAPHEI’s into the engine block should do the job. SAPHEI would probably work better than standard HEI due to radiators, frame members, water pumps, etc.

        Something like this would be very appropriate when dealing with the equivalent of Somali or ISIS “technicals” or etc.

        The magazine is interesting. It’s basically a Mannlicher-Schoenauer type rotary magazine, something that other than Ruger carbines in various calibers and the Steyr rifles, hasn’t seen much use in over half-a-century.

        The use of Belleville washers to avoid “bounce” in the magazine catch assembly is another item that hasn’t seem much use since about V-J Day. Oddly enough, their primary use has been in the compression triggers of land mines;

        https://en.wikipedia.org/wiki/Belleville_washer

        Two things I noticed when Ian was firing it. One was that the bolt bounces back and forth a couple of times with each cycle. With extended use, this could increase wear on the bolt locking lugs, and hopefully has been attended to in the production model.

        The other was that every time Ian fired it, the muzzle moved up and to the right. Since this weapon is a purely “right-handed” proposition anyway, a muzzle compensator ported to push the muzzle down and to the left might be a useful modification.

        cheers

        eon

        • You missed some other applications of the Belleville washer/spring technology: Machine gun buffers of a mechanical nature. The original MAG58 had such a buffer, and I believe that the early UK versions of the L7 did, as well. In US use, the M-240 soon transitioned over to a hydraulic buffer like the M-60 had.

          In landmine use, the Belleville spring is a bit of a dog’s breakfast… The US and a few others use them, to ensure that the fuses actually work, but the side effect is that the mines become susceptible to blast overpressure. Soviet mines stuck with tried-and-true cheaper coil spring setups in their mines, or relied on something being broken to initiate the firing train. As such, their mines were notoriously less susceptible to blast overpressure, and since we relied on the Bangalore Torpedo and various other rocket-propelled line charges (even before the malodorous MICLIC), well… Let’s just say that there would have been a bunch of really disappointed (not to mention, in all likelihood, dead…) Combat Engineers on the US/NATO side. See, we never actually tested against Soviet mines, until we captured a bunch after Grenada… We always used our own dogfood, so to speak, for testing. Which was a huge error in judgment, to my mind.

    • The info in MF says “gas operated”. It looks to me like the previous, older version which had been seen in various sources for years.

  5. Until today I do not ever remember thinking of any 20mm as a grenade. I knew of all sorts of shotgun rounds that were very different, but none of them were named as grenades.

    Grenade is, apparently, named after the pomegranate. The first rifle grenades were desperately invented ways to allow grunts to fire grenades rather than throw them. Was the M79 the thing that turned grenades into anything the infantry were given to fire out of a gun like weapon?

    • According to query in English wikipedia Shell (projectile)
      All explosive- and incendiary-filled projectiles, particularly for mortars, were originally called grenades, derived from the pomegranate, so called because the many-seeded fruit suggested the powder-filled, fragmenting bomb, or from the similarity of shape. Words cognate with grenade are still used for an artillery or mortar projectile in some European languages.
      While I don’t know about accuracy in case of English language, indeed at least in Deutsch during World War II term derived from that was used to denote cannon shells (see Sprenggranate)

      • “Panzergrenate” means tank shell if I’m not mistaken, and it’s quite fitting considering the intended victim is a tank. Penetrate and then detonate- very gruesome if the immediate human casualty happens to be hit directly by the projectile before it explodes inside the vehicle…

        • Panzergranate means “Armor (piercing)shell”- it’s more properly Panzersprenggranate, the “spreng” part meaning “explosive”.

          As for the whole “pomegranate” thing, the first hand grenades in the West were copies of Chinese grenades, either hand thrown or launched by catapults. They were developed in the mid-12th century AD in China, and spread to Europe by about the mid-14th Century.

          Originally, they had casings of fired clay (pottery, IOW) and were called “thunderclap bombs” in China because of the noise they made. Some were made a bit more lethal by adding bits of broken pottery or even gravel to the black powder, which was a fairly weak mixture, about 66% saltpeter, with charcoal and sulfur making up the other 33% in roughly equal proportions. This was a low-brisance black powder, more deflagrative than actually explosive.

          About the mid-13th century the Chinese had developed black powder with 75% saltpeter, 15% charcoal, and 10% sulfur- the same as the modern standard used since the beginning of the 18th Century in the West. They also started making their bombs with cast metal casings, usually cast iron. They called these “thundercrash bombs”, because they were not only louder, but they also generated a more powerful blast and threw out killing shrapnel; the world’s first fragmentation bombs.

          The “grenade” thing come in because all these bombs were spheres about 4 to 6 inches (10 to 15 cm) across, with a length of fuse sticking out the top. If you’ve ever seen Boris Badenov toss a bomb at Rocky and Bullwinkle, or seen the two nitwits doing it to each other in Spy vs. Spy in Mad magazine, you’ve seen these early bombs.

          The Spanish adopted them along with all other gunpowder weapons. And they were the first to notice the resemblance to a pomegranate. Or, in Spanish, Granada, and yes, the city and province in Spain are named that because they were famous for their pomegranate crop.

          So now you know.

          cheers

          eon

        • No most tank ammunition is HE and used for reducing targets like bunkers and artillery pieces to support infantry. That dynamic only started to change during the Cold War when the West had al mania for destroying hordes of Pact tanks, and tankers started to think they were knights out to joust other tanks, at least in popular imagination if not reality.

          • But has ‘grenade’ meant any infantry fired HE round since the M79 in the USA? I would have called this gun a cannon if the title of Ian’s video not called it a grenade launcher. Simple definition: solid shot = gun: exploding shell under 40mm = cannon. A grenade would have been 40mm or bigger.

  6. Bolt bounce is there to stay, part of the inertial recoil system. Has to since the bolt will go too far forward during chambering.

    • Yes, but there is an overtravel that could be adressed with an hook to catch the bolt like in the FAMAS or hk 416

  7. It would probably require gas operation instead of inertia operation, but a version firing the .50 BMG round and equipped with an 18- to 20-inch barrel and a 20-round magazine would make a vicious short-range thumper, and cheaper to feed.

      • It must be noted that 12,7×99 NATO and its Warsaw Pact equivalent in form of 12,7×108, both were created for dual anti-aircraft and anti-armour purpose (generally, term anti-mechanization would fit there), when armour of AFV was still so thin, that it was reasonable to assume that such cartridge will pierce most of armoured vehicles then used.
        To attain highest armour-piercing ability with then used technology, impact velocity of projectile should be highest and cross-section area (that is area of circle of diameter being equal to bullet diameter), when in case of HE shell impact velocity is not important, but how much HE filler is important, more is better, so bigger shell is better, lower velocity is acceptable cost. For example see Luftwaffe’s MG 151 vs Luftwaffe’s MG 151/20.
        As said before 12,7×99 NATO was created in “better AP effect” rather than “better HE effect”, but for that second purpose I think following cartridges would be better:
        13×64 from MG131, there even existed hand-held machine gun for it namely STL 131-VI-3, see 3rd photo from top here: http://www.bratishka.ru/archiv/2012/04/2012_4_14.php crafted by German engineers from Ikaria factory in 1945-1946 under soviet control
        .50 M48 used for spotting* in recoilless rifles, shorter than 12,7×99 NATO: https://naboje.org/node/4618
        ·50 Vickers, developed during Great War from ·600 Nitro Express, used in Vickers machine gun of that caliber, also shorter than 12,7×99 NATO: https://sites.google.com/site/britmilammo/-5-inch-vickers
        11,35×62 Madsen, used in 1930s by Argentinian Air Forces: https://naboje.org/en/node/9022
        *this cartridge has trajectory similar to said recoilless rifles and projectile after hitting give puff of smoke, if it is where target is then you fired recoilless rifle

        • is: “(…)cross-section area (that is area of circle of diameter being equal to bullet diameter)(…)”
          should be: “(…)cross-section area (that is area of circle of diameter being equal to bullet diameter) smallest possible(…)”

  8. This design is so elegant, I want to put it in an evening gown and take it out dancing…

    And by dancing I mean the gun range. Any gun range…

    I’ve been toying with a concept for years now on how to mitigate the recoil of a 20mm to make a man-portable weapon. Leave to South Africa to come up with not only a simple solution, but one that purposely compensates for all the physics involved with such heavy duty recoil impulses.

    And the PAW is so aptly named, Personal Assault Weapon…

    Let’s issue one per squad, like a Heavy DMR? ;- )

    Imagine if every Higgins boat on D-day had a half dozen of these going ashore during the assault. Might have been less comfortable in those defending pillboxes, eh? Might have been over by lunchtime. Then on to hegerow country…

    Practical? Ridiculously so. So much so, that I am suprised this hasn’t been developed much sooner. Hundreds of real world applications. (Anyone say counter-sniper?)

    Well thought out? Absolutely. Those who hate on bullpups really need to work hard to explain why this example of the type would be somehow less useful or ideal than a “conventional” layout. I believe they call that an Oerlikon, and it is decidedly a crew served, non-man portable weapon system.

    Functional? Precisely. Most any real elegant designs are such because of their inherent simplicity to begin with. Why wouldn’t nested or captive springs on an inertial system be preferred on such a whopper chopper recoil impulse such as a 20mm, over and above gas? Springs have less failure points, and are more easily replaced in the field, than all of the various components of a gas system.

    The designer was right, on coming back around to inertia system, because it simultaneosly cycles action, but also mitigates recoil. But the real genius is putting everything on sliding rails so that you maintain compact size, while allowing reciprocation of working parts. And the 1000m gratuated optics mount? That’s John Moses type thought processing…

    All in all, a gorgeous and seemingly well executed tool with myriad applications. Well done.

    (And thanks Ian, for sharing with us some real innovative designs, as well as all the rich historical regular features. I’ve been a long time viewer, first time posting comments. You have, hands down, one of the most interesting sites on the Web. And your regular comment posters are an amazingly knowledgeable bunch of guys. Keep bringing us the goods, thanks)

    • “Oerlikon, and it is decidedly a crew served, non-man portable weapon system. ”
      Not so fast. Oerlikon offered wide array of 20 mm caliber weapons, but ALL used much powerful cartridge, to reiterate: this weapon use 20×42 cartridge with muzzle velocity around 300 m/s, Oerlikon weakest cartridge option was 20×70 RB with muzzle velocity 550…575 m/s. Additionally Oerlikon system was full-auto, while this is self-loading.

  9. I have discussed this gun with the company representatives at military fairs, and they told me that the standard loading is the Target Practice, with an inert steel slug. This is great at opening locked doors and as a close-range anti-personnel ammo (it might not penetrate high-level armour, but you wouldn’t want to be hit by one anyway). The HEI stuff is for anti-material targets – using it against people could be legally tricky.

    It’s worth noting that the same 20 x 42B ammo is used in a belt-fed machine gun….

    • Hm. I could see that giving things like FAVs and light helos a bit of extra punch without the weight and recoil penalty of, say, an M2 12.7 x 99mm on an OH-58D.

      As one Kiowa W pilot told me, “Always apply some right rudder input before triggering the ‘fifty’ on the lefthand mount.”

      (It was supposed to be automatic. Accent on the “supposed” part.)

      cheers

      eon

        • I’m gonna go out on a limb and guess that he means “Fast Attack Vehicle”, which used to be a thing, back in the day. Now it more-or-less means anything hauling ass around the FEBA with little or no armor…

      • “without the weight and recoil penalty of, say, an M2 12.7 x 99mm on an OH-58D.”
        12,7×99, low-recoil, low-weight, aviation application? This reminded me about Robinson machine guns, which were created yet back in 1940s, in Australia.
        Citing: http://www.falfiles.com/forums/showthread.php?t=76174
        [Robinson] Model 5, having less than half the weight of the .50 cal Browning with the same barrel weight, created considerable interest in Australia. Tests on a stiff mounted reaction tester indicated only 15% of the peak trunnion reaction, but what was amazing was that the gun had a much shorter inboard length than any .30 cal machine gun then available.

  10. IIRC the 40mm grenade fuse isn’t armed until it rotates a certain number times. Somewhere around 15 meters I think. Reduces the chance of the operator blowing themselves up or their whole team if they have an accidental discharge inside a vehicle.

    Do the 20mm rounds have any such safety feature built in? If I understood correctly the 20mm projectile is the same as what’s used vehicle mounted weapons with a new(shorter) case. Not a a projectile designed from the ground up as an infantry weapon.

      • You’re right the LG6 seems to be in roughly the same category: single-person self-loading grenade launcher. The extended effective range of the PAW doesn’t have much competition, except perhaps from the US (canceled?) XM25 which uses a 25mm projectile that is very expensive.

        • I think the main advantage of this weapon is, if I heard Ian right, a relatively flat trajectory for area effect to 1000m and point shooting capability out to 600m. I get that a 40mm grenade carries more HE, but, again, like Ian said, it has a very rainbow trajectory.

          The PAW is more “put a couple rounds right now through that 2nd story window on the left…” type of weapon. It’s the flat arc, the 20mm power, the six round mag, and the overall compactness, that make it an ideal squad support weapon.

          And this, not to the exclusion of, but in addition to, all other organic squad weaponry.

          In my mind, this functions more as a companion to an LMG. It’s handier than a Barrett .50 in terms of size, and while yes, that recoil looked heavy, it did not appear prohibitively so.

          It just seems, like the VBIED example given, that there are just tons of uses for this gun in a firefight. The distances of engagements in Afghanistan come to mind.

          Then there’s economy of ammunition concepts at play too. Instead of having a squad burn mag after mag at an enemy, without necessarily neutralizing the threat, the PAW equipped soldier accurately drops a few rounds at enemy muzzle flashes.

          In much of the world, in that type of scenario, someone uses an RPG. Couldn’t the PAW achieve that same desired effect, with much greater accuracy? (Save the rockets for armored threats, etc.)

          I simply think the designers wanted to neatly fill the gap between say an R4 and the heavy weapons. Compact, transits safely, and quite user friendly considering just how powerful the round is.

          It’s not trying to fill the roles other weapon systems already do so well, the intended purpose is to do one thing extremely well.

          In twenty years, these will become commonplace in armies throughout the world. The logic is just simply there…

        • “US (canceled?) XM25 which uses a 25mm projectile that is very expensive.”
          Last line in XM25 CDTE (Counter Defilade Target Engagement) query
          https://en.wikipedia.org/wiki/XM25_CDTE
          section is: April 2017 – Army cancels XM25 contract with Orbital ATK.
          Although how this does affect state of that weapon I don’t know, it is STANDARD or SUBSTITUTE STANDARD or OBSOLETE or yet another state?
          Anyway slowdown (halt?) in development appears to be caused by some worries about Declaration Renouncing the Use, in Time of War, of Explosive Projectiles Under 400 Grammes Weight. This is really weird for me, as USA is NOT signatory of said Declaration, which is active ONLY in case of war between signatories, namely Austria-Hungary, Bavaria, Belgium, Denmark, France, United Kingdom, Greece, Italy, the Netherlands, Portugal, Prussia, the North German Confederation, Russia, Sweden-Norway, Switzerland, the Ottoman Empire, Württemberg.

          • We can only pray that that POS is dead…

            I think I’ve gone on for paragraphs about why I’m personally opposed to the entire concept of the XM-25, particularly based on the cost of its rounds and the system overall. This PAW is a different kettle of fish, entirely, due to its far lower costs and less reliance on hand-wavium.

            The root problem with these weapons is this: You cannot attain enough accuracy with them from the average infantryman’s shoulder to be effective much past 200 or so meters. That’s just a fact of life. The concept for the XM-25 was always precision fire, dropping a 25mm grenade into a window or bunker slit out to about 600-800m, and having it detonate inside the bunker, room, or overhead of a sanger. The idea isn’t totally ridiculous, were the weapon to be mounted on a tripod, and firing bursts, but… Off the shoulder? Without even a bipod? WTF? Carlos Hathcock probably couldn’t make that work, especially under fire. And, the firing solutions for these abortions? My informant who was with one of the testing units that had them in Afghanistan told me that the only way you could get the required angles to drop the round where it needed to be during a couple of engagements was to stand out in the open, with the weapon raised to the shoulder at high angle… His take on the weapon was that it was a recipe for expensive failure and a bunch of dead gunners.

            Similar issues are likely present here for this PAW, but with the lower costs involved…? I’d like to have one for the near-range envelope discussed, and dealing with VBIEDs and other such close-in issues.

          • “Off the shoulder? Without even a bipod? WTF?”
            Russian developed what they called “sniper” grenade launcher (with “sniper” always in quotes) in 1990s, namely ТКБ-0249:
            http://zonwar.ru/granatomet/ru4nie/Arbalet.html
            caliber 30 mm (same round as AGS-17), mass 10 kg, magazine capacity 5 or 10, has bi-pod and its construction make felt recoil milder. Given muzzle velocity is apparently error (75 m/s is stated but AGS-17 is 185 m/s, possibly digit 1 was lost and should be 175 m/s)

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