Examples of these include-
- Ring airfoil grenades- for flat trajectory shooting of either riot control or explosive.
- Multiple loadings -for example, an anti-ambush round consisting of a canister rounds and a Ring airfoil White Phosphorus grenade. Multiple loadings of M203 rounds are also possible.
- An incendiary round based on the German Hafla DM 34.
- A cartridge flow-stream flamethrower.
- A Flame capsule grenade containing Thickened Pyrotechnic Agent.
- Multi-shot canister loading (either multiple barrel or superimposed). More on this idea on the MetalStorm page.
- Grapple and line.
- Underbarrel version of the Brunswick RAW.
- A 7-9 barrelled “Volley Gun”, each barrel loaded with several projectiles. This would offer a longer ranged alternative to canister with better penetration.
- Windscreen penetrating round (detailed elsewhere).
- Depth-fused Anti-swimmer projectiles.
- Door buster rounds
DGLs loaded with OICW rounds may be possible, but unless the rifle is fitted with a Fuse Setting Interfacer these will only function as impact fused projectiles. A simple interface unit where the detonation range is manually selected could be fitted to a rifle or made part of the disposable unit.
It has been suggested to me that fired launchers should auto-eject from the rifle - this would be a good feature so long as this mechanism doesn't operate when the launchers are being fired handheld.
I've called these devices disposable -should be cheap enough to be treated as disposable but for training purposes they may be capable of being reloaded several times.
A friend suggests an alternate strategy:-
"These are a good enough idea that I suggest a small additional wrinkle: make two models.
M1 is a robust steel and alloy version that can be reloaded by the soldier. This is for economical training purposes.
M2 is a cheap plastic and fiberglass version, ideally w/ a break-apart feature that prevents it from ever being fired more than once. This is for advanced training and, esp., for war. If they're disabled by firing, no enemy can scavenge and reuse them, the way Charlie did much too well w/ discarded US ordnance in Nam.
Why a training version? Because men must practice w/ these weapons a lot"
I thought such a weapon might be useful in open terrain or against fast moving light vehicles. It may replace the light mortar on terrain that is too soft for such weapons.
The round I imagined originally resembled a modified rifle grenade mounted on a grenade gun case. Rocket assisted models would be possible.
The launcher is a single shot break open weapon with a straight-line layout, and an optic sight mounted halfway down the barrel. This arrangement allows the greatest flexibility over the form of rounds that can be chambered. Because the recoil would be greater than an M203, the furniture would be separated from the barrel by a recoil buffer and another buffer built into the butt.
Since I first thought of this idea I've added a few refinements:-
- One is that the weapon might also make use of Ring airfoil grenades.
- The second is that such a launcher could also fire the same rounds as the MK-19 GMG.
It is also possible that this weapon could be fitted with a discharger cup to fire larger projectiles. By fitting a discharger cup and providing a 40x53mm Ballistite round the HVGL could be used to project hand-grenades. Such a capability is most likely to be used in riot control applications for projecting tear-gas grenades. The German Granatbüchse 39, an anti-tank rifle modified to serve as a grenade launcher was often used with wooden bulleted rounds instead of "blank" ballistite cartridges. The TP 40mm round could be used in the same way.
The 3BT has two important advantages over other grenade launchers. The first is that its break-open action allows it to accommodate very long rounds. The second is that its recoil-reducing systems allow such heavier rounds to be fired with greater comfort. The increased kick is converted into a more gradual push.
For a projectile to be stabilised by rifling it must usually have a length to calibre ration of 7:1 or less. This is why arrows and long-rod penetrators use other systems such as fins. For a 40mm weapon this means we can fire a stabilised projectile of up to 11" length. This gives us a theoretical capacity of 77 cubic inches or 1.4 litres if the round was a true cylinder. This suggested that the 3BT can be used to project high capacity smoke or riot gas rounds. Since the sectional density will be higher than larger capacity rounds of similar weight, the round can be expected to travel to a greater range and with a flatter trajectory. Such capability will have both police and military applications.
The main HEAT round of the 3BT will resemble a finned rifle-grenade mated to a 40mm grenade gun case (although the case may be lengthened). There is good precedent for this; the first weapon to use the High and Low pressure principle was the German PAW 600, which used a modified 81mm mortar round attached to a modified leFH18 howitzer casing. By using fin-stabilisation in conjunction with a slipping ring system the HEAT round fired from a 3BT does not need to be spin stabilised. Therefore not only does the round carry more explosive than a M433 or M430 40mm HEDP grenade, but it uses it more efficiently. The 3BT loaded with such a round will be a useful anti-vehicle weapon, particularly when fired from confined spaces such as is likely to occur during urban combat.
Another useful capability offered by the 3BT is that it could be used to fire over-calibre muzzle-loaded projectiles. This has potential applications in the anti-vehicle role or for the delivery of chemical or conventional and thermobaric explosive loads. Over-calibre grenades would either have a spigot tail that fits over the muzzle or a tail that fits down the barrel. The latter will probably require the use of a ballistite round, while the former could possibly be a form of bullet trap. This may actually be feasible with a 40mm grenade since the fuse does not arm until 18 to 30m from the muzzle.
For an idea of the form of such a grenade we can look at the various designs of large caliber rifle grenade such as the Energa and Norinco Type-67. These are 70mm to 75mm in caliber and weigh between 1 ½ and 1 ¾ lbs. Fired by a rifle round they have a launch velocity of 42-62m/s, a direct fire range of up to 75m and a high trajectory range exceeding 250m. A skilled operator can probably drop a grenade onto the thinner top armour of a vehicle. Penetration for the South African copy of the Energa is given as 375mm of RHA, nearly 15". The Rhodesians often issued these to the point man of a patrol, giving him RPG level firepower during an encounter without the back-blast and added weight of a launcher. They also issued two types of ballistite cartridge, the weaker being used for close range hip or underarm firing.
Fired from a weapon such as the 3BT we can expect the range and velocity of similar sized projectiles to be much greater. This will make the 3BT a very useful weapon for anti-armour ambushes where the firer can operate from confined positions such as buildings or spider-holes.
Overcalibre grenades fired by the 3BT could be designed with tails that fit inside rather than over the outside of the barrel, allowing the projectile to be spin-stabilized by the rifling. An overcalibre round of similar performance and form to the 140mm Brunswick RAW is a possibility.
The 3BT could also be used to fire multiple grenade rounds. This might include a revival of the M397 bounding Airburst grenade. The larger capacity of the projectile would allow the use of more effective fusing systems such as proximity fuses that detonate the round before it reaches the ground.
There are many other possible roles for the 3BT. I see it as a very useful system for Low Aggression Military Operations. It can be used as a precision system to neutralize snipers, or can be used to fire a large capacity smoke round for defensive concealment. With Baton or Sponge rounds it can be used for long range Less-lethal force application. I can see a 3BT and a couple of dozen assorted rounds being part of the standard equipment of all vehicles on Peacekeeping or other LAMO type service. The 3BT may also replace the platoon mortar in some situations. Its range and accuracy would make it the obvious choice for target marking teams.
The Philippino company of Floro International offers a "High Velocity Grenade Launcher". Essentially a rifle that fires 40x53mm grenades. It appears to be a single shot semi-automatic weapon that uses recoil forces to open the breech and eject the spent case, rather like the mechanism of the Russian PTRD-41 anti-tank rifle. According to Jane's Infantry Weapons 2004-5 there are two models. The M2 is intended for firing from a bipod and weighs 10kg, while the M1 is for tripod or vehicle mounting and weighs 16kg. The M3 tripod designed for the Browning HMG can be used. The canister round contains 200 balls of steel shot and has a range of 45m.This weapon is nearly what I envisioned for the 3BT. What is not apparent is if the breech clearance is sufficient to accommodate extra-length rounds. A version with a barrel that can be tipped up to load these should be possible.
40mm Mortar
40 x 53mm Grenades could be fired from a simple launcher of less than 4kg weight if only indirect fire was used.
Such a weapon would be simpler than a 3BT and could be created from a re-chambered M79 with the butt reshaped to prevent shoulder firing. Such a weapon would be useful to Scout platoons, allowing them to illuminate or mark targets at ranges in excess of 700m. A double barrelled version of such a mortar would be possible. Batteries of such weapons would be useful anti-ambush devices for light vehicles.
AMR launched Rifle Grenades?
A option that has not been investigated with AMRs is their potential as grenade throwers.
When the WW2 German PZB 38/39 anti-tank rifle became obsolete many were fitted with cup dischargers so they could launch grenades, including the various hollow charge models comming into service.
To the best of my knowledge, spigot-tailed rifle grenades have not been built for AMRs, but the idea may have potential for both indirect and direct fire roles. Use of such grenades would give an AMR team an organic capability to illuminate distant targets during night actions.
Anti-windscreen round
These are intended to be used in weapons such as the M203, the multi-shot grenade launcher and the Disposable Grenade Launcher.
One option is a very soft HESH round -probably too soft to feed through an automatic action. This flattens against the windscreen and is fired by an inertia fuse.
If this doesn't perform as expected then a warhead with three or more horns should be tried.
Many crossbow bolts had a square cross section with a raised point in each corner. Payne-Gallwey notes “Other bolts had square-faced heads with four small points, one at each corner of the head, so that they might not glance off armour, but give a straight and smashing blow to mounted men wearing breastplates and helmets, against which the end of a sharp projectile might break, bend, or turn aside”. In other words, one or more of the off-set points would catch on the target and act as a pivot to move the bolt into a more perpendicular aspect. This mechanism is illustrated here, although this example uses an aerodynamically inferior soft metal disc. I have seen a whaling harpoon head that had a quartet of points at its tip to act in the same way as a medieval crossbow bolt.
The same effect could be achieved with 40mm HEDP grenades by gluing a hard plastic “crown” to the nose. Rounds like the M433 are only used with single-shot and revolver mechanism weapons so this addition would not affect operation. It would not work with higher velocity rounds for automatic grenade launchers but many of these in the near future will be using programmable fusing to achieve optimal stand-off distance.
As one or more points of the crown hits the target it causes the round to flip over and turn perpendicular to the surface of windscreen. Fusing might need to be an inertia fuse with a short delay.
Adhesive smoke projectiles.
These are intended to be fired from M203s, 3BTs or disposable grenade launchers to mark targets for air or artillery strikes.
The shell shatters on impact and the contents stick to the target and produce a column of smoke. This allows a building to be marked high up where the signal is more visible and also allows mobile targets such as vehicles to be marked. Ideally this round should also be visible at night to both the naked eye and night vision systems.
It is possible that this role could be performed by a grenade filled with some variant of napalm. In this case the round would also find other uses.
From a World War Two American publication on tank-infantry co-operation:-
"Tracer fire proved unsatisfactory for designating targets to the tanks. The best method was the use of red or violet smoke grenades. The full-charge grenade produces too much smoke and obscures the target. However, if the fuze is unscrewed from the grenade and half the charge removed, an adequate amount of smoke will be produced."
“Rifle projection of the grenade is desirable for longer ranges. Best results are obtained by arming the grenade before firing as this will then give a trail of smoke to the target.”
REF.
By the Author of the Scrapboard : | |
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 | Attack, Avoid, Survive: Essential Principles of Self Defence Available in Handy A5 and US Trade Formats. |
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 | Crash Combat Second Edition with additional content. Epub edition Second Edition with additional content. Crash Combat Third Edition Epub edition Third Edition. |
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