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TranshumanSpace

Weapons: Crewed Infantry Support Weapon (CISW)

The 15/25mm CISW (Crewed Infantry Support Weapon), aka “Multicannon” was developed by a Belgium company, although inspiration was obviously drawn from the much earlier American XM307 (High Tech 4e p.144). As is not unusual in the THS worlds, a number of companies produce similar or identical weapons, with or without license.
The CISW is an infantry support weapon designed to be used by a two-man crew. The gunner carries the launcher with the fire-control system (35 lbs, Bulk -7). The assistant gunner carries the tripod and ammunition. Additional ammunition may be carried by other squad members. The CISW is also mounted on some robotic combat systems.
The CISW is an e-mag weapon so there is no muzzle blast nor flash. The e-mag system allows rounds of differing calibres to be fired without modification to the weapon. The CISW can fire either 15 mm “kinetic” rounds or 25 mm explosive grenades. The CISW provides a unit with both an automatic grenade-launcher and a heavy machine gun.
In grenade-launcher mode, the weapon can be used against personnel in the open or behind cover, and lightly armoured cybershells and vehicles. Machine-gun mode gives increased hit probability against airborne and fast-moving targets.
The CISW has dual-feed. Usually the left port is used for grenades and the right for bullets. The feed modules can be exchanged or two of the same type fitted.
The tripod is made of very lightweight materials but includes the three D cells that power the weapon, so weighs 17 lb with these in place.

Kinetic Ammunition

The finned kinetic rounds are known as “bullets”, “slugs”, “solids” or “fleche”. The latter is French for “dart” or “arrow” but the rounds are often mistakenly referred to as for “flesh”. Kinetic rounds are available in the usual THS bullet options available for other bullets (THS 3e p.157; THS:CT 4e p.64), the exception being those that would result in a plastic and non-magnetic round.
The relatively light weight of the weapon limits how much recoil it can handle. RoF in machine-gun mode is 7, Rcl 2. Semi-automatic and five-round burst settings can be used in machine-gun mode. Muzzle velocity of 15 mm projectiles is 900 yds/sec. AP: 7d x 2 (2) pi++.
Kinetic rounds weigh 0.1 lbs each, including feed links. A 100 round belt weighs 10 lbs.

Grenade Ammunition

Grenades are usually either HEMP (Dmg: 6d x 3 (10) cr + linked 2d cr ex [1d+1]) or thermobaric (Dmg 8d cr ex inc.), or a mix of the two. Grenade fuses are programmed just before firing. Options included impact/point detonation, timed-airburst or airburst with impact override. Impact mode has the options of superquick detonation or variable (programmed) delay. Airburst mode is achieved by a timer and the fuse includes an accelerometer to compensate for velocity variations due to head or tail winds. This also compensates for the grenade being slowed by passing through cover or vegetation. Airburst includes a “window” option that detonates the grenade 1.5 yards beyond the lased distance. (HT 4e p.144)
Each grenade weighs 0.3 lbs. Self-destruct is 24 seconds after firing. Grenades are loaded by a 30 round drum-magazine, (often called a “can”) that weighs 10 lb loaded.
Max ordinate for grenades a standard/subsonic velocity is 100 yds/430 yds. This may limit use of the weapon within large buildings.
Time of flight to 2,2000 yds at standard/subsonic velocity is 9 secs/21 sec.
In addition to the HEMP and thermobaric rounds, two training rounds are available. The first is an inert warhead fitted with a small tracer element. The second is a flash-bang munition (HT-3 aff (5yd.)). This variant may also be used as a less-lethal weapon to deter mobs. Threat as a small stun grenade [HT 4e p.193].
As a grenade-launcher the CISW has a standard and subsonic velocity setting. Subsonic mode is mainly used when high-trajectory, indirect fire is needed.
Standard grenade velocity 450 yds/sec. Standard velocity arming distance 35-55 yards.
Subsonic grenade velocity 250 yds/sec. Subsonic velocity arming distance 20-40 yards.
The light weight of the weapon limits fully automatic mode with grenades to RoF 4. In practice semi-automatic fire or two-round burst mode is more commonly used. 
The CISW fire control system (Acc+1) includes day, night and thermal vision with 1-6x video magnification (Acc +1 or +2) and recording. The fire control system uses a laser rangefinder to determine the correct range setting for airburst. The system also has a coincidence optical system for targets that cannot be easily lased. The fire control program can distinguish between different target types such as troops in the open, entrenchments, windows or vehicles. The operator or his AI can override the automatically selected fuse or distance settings.
Many nations have brought the weapon but the number of units sold has been modest. The weapon is most suited for company-level dismounted operations, which are not common outside of training exercises. Most actual dismounted combats on the THS worlds involve platoon-size or smaller units. Relatively immobile weapon systems like the CISW are vulnerable to many means of attack. More powerful or capable vehicle-mounted support weapons are often available, so CISW are seldom unpacked.
The relatively long minimum range of the grenade-launcher also limits its utility in some environments.
Operating a CISW uses GUNNER (MACHINE GUN) skill or DX-4 or other Gunner skills at -4. Values on the table are for APS-equivalent 15 mm ammunition. 
Weapon
Dmg
Acc
Range
Min. Range
EWt.
RoF
Shots
ST
Bulk
Rcl
CISW 15mm MG.
7d x 2 (2) pi++
5+3
1,800/7,600
35/10
7
100(5)
17M
-7
2
Grenade standard velocity
varies
3+3
2,200/3,600
35-55
35/10
4
30(4)
17M
-7
3
Grenade subsonic.
varies
3+3
2,200/3,600
20-40
35/10
4
30(4)
17M
-7
3