40mm Caseless Variable-Velocity Grenade Concept from Armor Development Group Shown Off at [NDIA 2017]

At the 2017 National Defense Industry Association’s (NDIA) annual Armament Systems Forum in April, Mr. Howard Kent of Armor Development Group, and Dr. Jeffery Widder presented a concept for a caseless grenade system which allows the user to aim by changing the muzzle velocity of the round itself. Their grenade design would allow a grenadier to fire on targets at varying ranges while maintaining the same firing angle as well as approximately the same impact angle.

The concept behind the new 40mm grenade design is similar to that of muzzle-mounted rifle grenade launchers such as the French system used on the MAS 36/51 and MAS 49/56 rifles. Unlike those weapons, which use a variable seating depth system to change the projectile’s velocity, the new grenades would use a variable vent system to change the launch velocity of the grenade. The shooter would change the velocity (and thus point of impact) of his grenade by rotating the grenade body in the sabot, exposing one of two different sets of gas vents, or no vents at all. Instead of expanding gas propelling the round directly out of the launcher, the concept uses internal pistons similar to those of US and Soviet silent rounds developed during the Cold War.

The concept has the advantages of not requiring the grenadier to change the angle of the rifle relatively to his shoulder to hit a target, as well as potentially allowing a much lighter firing platform. In the presentation, Mr. Kent and Dr. Widder pointed to the similar Batelle non-lethal launcher system which uses a lightweight spigot-type launch platform, and indicated that such a lightweight launcher could also be made for their similar grenade concept.

Batelle spigot-type nonlethal launcher mounted under an AR-15, without projectile attached

The system doesn’t seem to be without its downsides, though. Having to adjust the grenade on the spigot to adjust range seems like an issue when engaging targets which are rapidly changing their distance to the grenadier, such as advancing enemy troops. There is also no way to see which range the grenade is adjusted for from the firing position, and each grenade must have its range adjusted as it is loaded, potentially slowing firing rate versus existing designs. Still, the concept has a lot of potential, particularly the spigot-launched element derived from the original Batelle non-lethal launcher.



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 is also the author of the original web serial Heartblood, which is being updated and edited regularly. He can be reached via email at nathaniel.f@staff.thefirearmblog.com.


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  • Brett baker

    Didn’t the French develop a line of over the muzzle grenades? As I recall there was one version used regular cartridges fired on semi. Something like that might be better, if they could do it.

    • Rifle grenades were pretty common in the past (the M1 Garand and M14 both had adapters allowing them to fire RGs – the M16 family including the M4 can do so without any modifications), but were subsequently superseded by underbarrel launchers in most armed forces.

      The reasons are that rifle grenades have some technical disadvantages that make underbarrel launchers a bit more flexible, and rifle grenades are much harder on host weapons than underbarrel GLs.

      • roguetechie

        Yes, but the practice ones are retarded fun to run around with a giant grandma purse stuffed full of them and an AMD-63 with a Yugo grenade spigot installed screaming wolverines and salvoing 3 or 4 into a hacky sack circle while screaming

        ah realleh need to rent a zip car over and over between bump firing a full magazine of blanks into the air, pushing a kid off his RAZR scooter using it as an improvised getaway vehicle swan diving off the edge of the wall into the Willamette river screaming that you are sovereign salmon, which makes you a meat boat and interruption of your trip upriver to spawn is a warcrime

        • Brett baker

          It’s gonna suck big-time when the NorKs nuke Portland, bro.

          • roguetechie

            Meh, for me yes…

            For the rest of the country… Not really

          • Major Tom

            I can’t see it any worse than Russians in Colorado.

            Although the way Colorado is in terms of terrain and lots of armed folks out in the boonies, it would make Afghanistan look easy.

    • Kivaari

      Belgium led the way with both blank and ball capable grenades. From memory it was Meccar.

  • Major Tom

    I see one small problem with this. Private Snuffy will set these grenades to short range low velocity when he was trying to aim long range higher velocity. And then wonder WTF happened when his shot goes limp and short.

    • Kivaari

      I can see them always setting them to max range and just aiming differently.

    • noob

      Don’t worry, a short round happens to all of us one time or another.

  • I’m thinking a rocket assisted 40mm would likely be a lot easier to use in combat, and maintain a more consistent, flatter trajectory.

    The shell has a reduced powder charge that kicks the round out at 100fps or so, which after 10′ then ignites a small rocket motor in the base of the grenade. Possibly like a big version of the Gyrojet.

    Given that a 40x46mm launches at ~220fps, even if the rocket ‘only’ gets the round to 400fps, that would lead to a big increase in range. If they got velocity to 700fps, the 40mm could be used as a direct line of sight round, greatly improving practical combat accuracy, especially against windows and doors.

    • Edeco

      Huh, interesting… 220 fps, could get faster than that with a hai-jalai scoop.

      • aka_mythos

        Its more about range than velocity and in such a compact package they start to become mutually exclusive. The lower velocity also makes guiding it to it’s target less technically demanding. From people I know working with Raytheon, its fuzing and explosive load is pretty much a standard HEDP round with a rocket motor and a guidance module attached… utilizing off the shelf to keep down the price but likely limiting it to something similar to a conventional 40mm grenades velocity.

      • noob
    • Andy

      check out the Raytheon Pike. it’s mentioned in the presentation. it’s a guided rocket. drawback is length required. it sticks out of a 320 and abbot be loaded into a 203

      • mechamaster

        The “economic- unguided version of pike”,
        maybe it’s good concept. You can trade the electronic for extra explosive and rocket-propellant too.

        • That’s sort of what I was thinking it as – a smaller, much cheaper unguided Pike.

          Even something as small as an Estes rocket engine could greatly extend the range of a 40mm.

          The real trick would be building them so that the trajectory and accuracy was consistent shot-to-shot.

          But it seems like a much simpler and more effective solution then a variable range spigot propulsion system.

    • mechamaster

      Then you need the extra-lenght 40mm grenade

      maybe like the Extended Range Low Pressure (ERLP) 40×51mm or low powered 40x53mm, up to 400-800 meters.

    • Warren Ellis

      Sounds like a 40mm bolter round.

  • valorius

    I do not have much hope that these microprocessor controlled weapons will function as intended in a major war with a 1st rate power like China or Russia. I think many shenanigans will ensue.

    • noob

      Not least the destruction of all above ground chip foundries. Rod Barton was part of the Iraq Survey Group and wrote in his book The Weapons Detective that once he got a helicopter ISG found a suburban building with way too many air conditioners for a 1 storey office block. On gaining entry they discovered it was a 5 storey tall, underground, armoured oil refinery that had been imported in secret from Europe and assembled to provide gas for the Iraqi forces after all the above ground refineries were blown to hell.

      We’d need backup distributed, hardened hardware production facilitates if we want a steady supply of JDAM tail kits, or smart weapons would end up being too precious to use.

      And unfortunately high technology sits on top of a pyramid of lower technologies. If any of the links of the supply chain can be broken it will result in terrible shortages fanning out into all the dependent technologies.

      One prospect is that in this era of Strategic Arms Limitation and theater defense anti-missile systems, the most likely high intensity war would be a “broken back” nuclear war, where after the initial exchange neither side is sufficiently damaged to stop fighting and so conventional and tactical nuclear battles grind on for decades, poisoning the biosphere as each side digs their factories deeper into the earth in some kind of global Battle of the Somme.

      • Brett baker

        Got some great bad novels out of the idea, though

    • RocketScientist

      WTF are you talking about? The concept proposed, and being discussed here, is a purely mechanical system. There are no microprocessors at all? Are you confusing this with the Raytheon Pike? Or the XM25?

      • valorius

        Calm down son.

        • RocketScientist

          Huh?

          • valorius

            Be. Calm.

          • RocketScientist

            I’m quite confused, did you reply to the wrong comment? Who’s not being calm?

          • valorius

            Are you calm now?

  • Kivaari

    So the first illustration showing a casing is the wrong image? I think this idea stinks.

    • noob

      “Caseless” is relative. the brass case is not really necessary in a captive piston design, but can be added so that it will be compatible with legacy launchers.

    • The first illustration shows the caseless projectile in an adapter allowing it to be fired from existing 40mm GLs.

      • Kivaari

        That’s what I thought. It’s sort of a take off on the Russian caseless system, just with a rocket motor.

  • Kivaari

    If you need an M79 I see there is one for sale on Gunbroker for $6950. It’s in mint condition.

  • noob

    Remove the explosive payload, scale down to 12ga.

    SET RIOT SHOTGUN SLUGS TO STUN!

    **five minutes later**

    Well that concludes the non-lethal portion of tonight’s activities, SET SHOTGUNS TO KILL!

    • Kivaari

      That would be easy. The less lethal version shown is only 0.50 caliber (12.7mm) and a 12 ga. is 18.5mm.

      • noob

        It would extend the range of less lethal. The only point where you want the velocity to be below lethal is in the terminal phase just before impact. So if you know the range you can select the highest muzzle velocity that will give you that less lethal velocity after drag has done its work. This is more flexible than a fixed less lethal load where you need to get closer.

        • Kivaari

          Maybe on something like a 40mm sponge load. MOST less lethal stuff is taking place at rooms distance. A 12 ga. loaded with rubber baton is OK. For riot control, I see too many mistakes being made if there is an adjustable round. People are getting killed with less lethal stuff already.

  • mechamaster

    https://uploads.disquscdn.com/images/c182c9b683cee6e0179dc9ae0782c2c13e40c36fb82a7b4a637e84f9f9e5a6a9.jpg

    A caseless grenade launcher like the GP-25 family ( pict : okg-40 iskra ) with lightweight material less than 1kg and smart-grenade programming capable seems a better solution. The problem maybe it is louder than M203 series or spigot pneumatic launcher.

  • iksnilol

    [Heavy breathing]

  • Warren Ellis

    Is there any similarity between this idea and the Russian 40mm caseless grenades? Other than that their both caseless I mean.