Mauser 30x173mm cannon using ABM ammo.
An ABM-HEDP round should be suitable for most targets.
A "Mortar shell" could be used for high trajectory shots. This would have just enough propellant to cycle the action, the rest of the case being taken up by the warhead.
- The airburst capability would be useful against infantry or for firing over entrenchments. The 30mm ABM-HEDP round will therefore prove to be very useful for Reconnaissance by Fire roles.
- In the anti-material role it will also allow the warhead to explode at optimum stand-off distance.
Both the ABM-fused 30mm ammo and 30mm "Mortar" shells already exist or are in trial phase.
The co-axial Machine Gun will probably be a 7.62mm weapon, though it could also be the proposed .50 Hose firing flechettes and saboted penetrator rounds.
Pylon Mounts for IFV turrets
The mountings for the rocket packs and ATGW tubes could be constructed as pylon mounts, so a variety of other configurations are possible. At least one vehicle in each infantry company will probably carry a pod of Stinger-type SAMs. Other weapons such as mini-guns, smoke-laying GMGs or flame-projectors are also possible.
The Rockets would probably be based on the 2.75" FFAR. Current models of FFAR are designed as aircraft armament. The Mk66 rocket motor gives an initial velocity of 148 fps which rises to a maximum of 2425 fps at 397 m. Fuses such as the M423 arm at 43 to 92 meters while the M439 used with Flechette and MPSM rounds does not operate till at least 500m from the launcher. Such settings are fine for Airborne or Artillery applications but for direct fire from combat vehicles a rocket with a fast burning motor to give a higher initial velocity and fuse with a shorter minimum range would be desirable. Ground direct-firing may allow a shorter maximum range allowing warhead size to be increased. Rockets with flechette warheads will give the vehicle capability against both personnel, light vehicles and helicopters.
Laser guided versions of FFAR rockets will soon be available.
The FFAR rockets were originally developed as air-to-air weapons to bring down bombers. The 1950s F-94C fighter was armed with 48 FFARs instead of guns :- a 12 round pod on each wing and 24 in a ring around the nose. What is interesting is that these rockets were fired from blind-ended tubes. The FFAR is robust enough to withstand the pressure of firing this way. This suggest that FFARs could be fired from ground vehicles without backblast, meaning less risk to nearby dismounts.
The ATGW system will have one, preferably two missiles ready to launch. This could be TOW but a higher velocity weapon with some anti-helicopter capability will be better (see later). It is also possible that the vehicle could carry a mix of terminally guided, fire and forget and top attack munitions.
The ATGW tubes could also launch an unguided rocket with a HEAT-MP-Frag or HESH warhead and a fast-burning motor for high acceleration. The Missile Launcher rockets fill a similar tactical role to Recoilless rifles, being intended for close range anti-tank and demolition. Fired at higher trajectories they may have a useful longer range role.
We can't really consider IFV armament without some consideration of turret design. Most MG armed APCs and some IFVs with heavier armament have a crew of two :- driver and vehicle commander. The commander also serves as the gunner. He fires in support of the dismounted infantry and directs the driver to manoeuvre to facilitate this. In most armies the most senior soldier in a mechanized squad is the leader of the dismounted element. Some APC/IFV designs have a position for the Squad Leader when he is mounted, with his own hatch and vision blocks. This is most obvious on variants of the M113 such as the Turkish TIFV, Korean KIFV/K2000 and United Defense/FMC AIFV. These have two cupolas side by side, the one for the Vehicle Commander usually fitted with gunshields or a one-man turret. The BMP-1 and British Stormer also have positions for the dismount team leader.
Things get less clear when a vehicle has a two-man turret. The turret is a good position for the Squad Leader to occupy since it lets him view the lay of the land. Theoretically there should be no reason why a vehicle with a two-man turret can't fight with a two-man crew in the same manner as a vehicle with a one-man turret. In many armies, however, vehicles with two-man turrets are always operated with both seats filled. In the Bradley platoon the Platoon Leader rides in the turret but when he dismounts his seat is taken over by a fourth crewman, the assistant gunner.
The likelihood of battle damage and crew attrition means that it is probably prudent if two-man turrets are designed so that they can be operated by a single crewman. This means that both positions should have identical controls and equal access to sensor systems.
Bill Clarke writes:-
I like the idea of vehicles mounting both cannon and missiles. I would mount the Hellfire ATGM in 2x3 cell launchers on GAU-13 equipped Tankitas, but would also have IFVs with only this gun (for purposes of weight and cost).
PW: Since more GAU-13s would need to be produced, I suggest they be built with shallow rifling, a sort of "semi-smoothbore" to work better with the 30mm APFSDS rounds you have suggested.
BC: Also, the GAU-13 is an externally driven weapon, it's ROF could be easily set to a level that would be within the capabilities of the firing platform's recoil capacity. On a heavier Tankita, it could be set to the max. of 2,100rpm. On a LAV-sized vehicle, you could set it for around 800-1000rpm.
Also, it has a dual feed mechanism, so separate ammunition drums could be attached, giving the gunner the flexibility to engage with the appropriate ammunition type. Checked on the dual feed with an A-10 crewchief. Not used on the A-10, but it is a feature of the weapon.
I think I would use twin 1,170rd A-10 type ammo drums for tankitas, and a single 1,170rd ammo drum for a IFV. I would estimate that a 1 second burst (35rds) of 30mm 2:5 ratio (14 HVAPDSDU, 21 HEDP) would be more than enough against a T-80 or older tank, which would result in the ability for the IFV to kill up to 33 tanks with one drum- out to a range of about 1,500M. Surely, a 1 second burst would decimate any fortification that may be encountered. Remember, the HVAPDSDU rds also carry an incendiary effect, due to the pyrophoric nature of DU238.
Also, there's no question of the effect such a mix of ammo would have against personnel, light vehicles, and aircraft of all types. Not even an A-10 could withstand 35 hits of the above mentioned ammo.
PW: Such a high rate of fire may be unnecessary when firing in a ground to ground role. I'd be inclined to experiment with a ten round burst mode.
BC: Also, since I have proposed such an IFV be based on the excellent, and readily available M113 (with suitable armor upgrading), which holds 11 infantrymen, I do not think a 55gal. sized drum of ammo would be size restrictive. The M113 could still easily hold an 8 man dismount squad. I also prefer the concept of a remotely operated gyro-stabilized turret. This would keep weight to a minimum, and really help to keep the vertical profile to a minimum. I would think the same wep./turret package, but with twin 1,170rd drums, would be highly effective and desirable for a two-man M-551 based Tankita.
Further, I would arrange my force structure into teams, with 3 IFVs operating with 2 tankitas. This would give each Plt/section 5 GAU-13's, 12 Hellfires, and 24 dismount infantry. I believe this would be a very powerful mix of forces/weapons.
A GAU-13 equipped AFV would CLEARLY outperform either a 75mm, a 75/120mm, or a 30mm or 40mm single or twin gun design against tactical attack fighters. When you lack a dedicated AA targeting system, there is simply NO substitute for ROF. A GAU-13 equipped vehicle has the ROF to hit an airborne target without needing serious computer/radar assistance.
A GAU-13 @ 2,100RPM and 4,200fps (or 4,400+FPS with your proposed shallow-rifling), with a 2nd GEN.FLIR is CLEARLY the best choice against 'fast movers'. It would also easily eclipse any of the other primary armament configurations for target (infantry) suppression as well.
One final consideration that leans heavily in the rotary cannon's favor is the huge psychological impact that 5 30mm gatling cannons would cause to the enemy. Having seen actual A-10/Avenger live-fire demonstrations, I can say that the sound is terrifying and LOUD!
PW: The 30x173mm gatling is probably well capable of anti-tank or demolition roles. Personally speaking, I think the 30mm PP-ASP/ATGW/FFAR is a better option for the M113, for weight considerations if nothing else. For a vehicle of Warrior or Bradley weight, or a Tankita the GAU-13 does have more appeal. I can easily see a Bradley hull mounting an unmanned turret with a podded GAU-13.
Many new IFVs and upgrades are proposing single barreled 30x173mm weapons such as the Alliant Technical Systems Bushmaster II or Mauser MK 30. The 30x173mm round is the same round as used in the GAU-8, GAU-13 and Oerlikon KCA. Muzzle velocity is in the region of 1,035m/s for HE-T and 1,450m/s for APFSDS.
The Bushmaster II can also be adapted to use the 30x170mm ammo used with the L21 RARDEN and Oerlikon KCB.
As an aside, it is worth remarking that the design philosophy behind the RARDEN was somewhat different to that of most automatic cannon. Whereas most weapons can be considered to be overgrown machine guns the RARDEN was designed with accuracy as a priority and is more of an SLR on steroids or a supersize anti-tank rifle.
35mm and 35/50mm Cannon
The next generation of Bradley or Warrior weight IFVs will probably mount larger calibre guns, one likely choice being a 35mm weapon such as the 35/50mm Bushmaster III, Rheinmetall Rh 503 or South African LIW EMAK.
The Bushmaster III has a cyclic rate of 200rpm and uses the same 35x228mm ammo as the Oerlikon KD series (KDA, KDF etc) so muzzle velocity will be around 1,400m/s for APDS and 1,175m/s for HEI.
The AHEAD round is an anti-aircraft shrapnel round using programmable air-burst fusing and will probably see numerous applications against both ground and airborne targets. It would be a useful round against small flying objects such as anti-tank missiles and UAVs. The 35x228mm KDA cannon is an effective anti-aircraft weapon used in systems such as the Gepard Flakpanzer, Marconi Marksman turrets and a single barreled mount with associated air to ground firing systems is being developed for vehicles lighter than MBTs. Twin 35mm Oerlikons have been demonstrated mounted on light tracks such as the M548 (M113) and the weapon is also used in the GDF guns used in systems such as Skyguard. The KDA has a cyclic rate of 550-680rpm and there are obvious advantages to having ammunition common to both IFVs and ADA vehicles.
The Rheinmetall Rh 503 weapon has a rate of fire that can be varied from 150-400rpm and can be operated manually as a single shot weapon in the event of power failure.
All of the weapons designated 35/50mm are designed to use bottle-shaped 35x228mm but can be converted to use cylindrical 50x330mm Supershot rounds by simply changing the barrel and a few minor components. The 50x330mm occupies the same space as the 35x228mm so the same number of rounds can be carried and they can be stowed and handled in the same way. What is interesting about the Supershot is that not only is the APFSDS round saboted but so too is the proposed HETF-T round. This feature combined with the larger case capacity and a tractor sabot means that switching to the larger calibre does not mean a reduction in velocity or increase in Time of Flight. These characteristic are in fact likely to be improved. The intention seems to be for the HETF-T round to have programmable-fusing as a standard feature, giving the gunner the option of air-bursting shots to attack targets behind cover and increased hit probability against fast moving targets. The setting of different rounds in a burst can be varied to give a wider pattern of coverage. It is possible that we will also see some full-calibre rounds for this weapon such as canister and HESH. Rheinmetall claim their 50x330mm APFSDS round has 50% more power than their 35x228mm APFSDS. The 50mm APFSDS-T fires a 640gm tungsten penetrator at a muzzle velocity of 1,600m/s. A short burst of such rounds will probably neutralize lightly armoured MBTs such as the widely used T-72. HESH and canister loads for this weapon might also become available.
I've just been informed that the British made Starstreak missile has been sucessfuly fired against ground targets and has shown sufficient penetration and destructive capabilities to make it a very effective anti-MBT system. In brief, the Starstreak darts are claimed to each penetrate over a metre of armour at a range of 6000m - nearly twice the range of a TOW. While TOW takes 21 seconds to reach 3,750m Starstreak takes less than 5 seconds to reach 6000m.
Mounting Starstreak on a APC or IFV instead of TOW gives a considerably more capable and versatile system that can kill tanks, jets, armoured helicopters and destroy buildings. Starstreak has nearly twice the range and a fraction of the flight time, making it harder for the target to deploy countermeasures or counter-fire.
The turret of a vehicle that mounts Starstreak will need to have a laser. Correctly designed this can also serve as a range-finder for a OCSW or an autocannon using ABM ammo. Such a laser can also designate targets for laser-homing projectiles such as FFAR, Hellfire, Copperhead, Paveway or Maverick.
Minimum range of the Starstreak is given as 300m though whether this is an arming range or control range is not stated. Given the high launch velocity of the Starstreak (0 to Mach 3 in under a second) it probably still has sufficient accuracy and kinetic energy to prove effective against targets closer than 300m.
For close range operations such as MOUT an idea that does suggest itself is "Dumb-streak" using the Starstreak motor to propel an adapted 120mm tank or mortar shell.
The One-man turret system proposed above would integrate nicely with the Tank-CIWS system that has been proposed. The Tank-CIWS would be mounted behind the troop hatch and be raised up on a stalk for a 360° field of fire. The LIDAR, Millimetric Radar and Thermal Seeker of the Tank-CIWS would search for targets or threats while the systems on the one-man turret would be used to attack and designate.
Ground Launched Hellfires.
On his webpage Carlton Meyer reports that AGM-114 Hellfire Missiles have been successfully launched from ground vehicles. For trials purposes a modified HMMWV was used but for combat a vehicle such as a M113 or Bradley would be more useful.
Carlton points out that Fire Support Team Vehicles (FIST-V) already have laser designators for guiding helicopter-fired Hellfires so it should be practical to launch Hellfires from launching racks on a FIST-V so they could destroy tanks or any targets up to four miles away, including attack helicopters. For some missions a missile armed vehicle can be more effective than an expensive helicopter that can be shot down.
An advantage of the Hellfire is that is has a Lock On After Launch (LOAL) mode that allows it to fired from a vehicle that only exposes itself momentarily and then home in on a target designated by another unit. There is also now available the Brimstone missile, a fire and forget version of the Hellfire using a millimetric seeker.
Laser designators are likely to become standard equipment on many forms of combat vehicle so it is likely that we will see increased use of missiles such as Hellfire in a ground launched role.