Sunday, 30 December 2018

Weapons: Grenade Launchers for Transhuman Space

I will add more details at a later date. Blogger always mucks up tables and I do not have the time or temperament today. In the meantime, the grenade launcher pages of High-Tech 4e will prove useful, particularly the section on the M29 on p.144.

Whilst mini-missiles are a very common weapon in 2100 they have not totally replaced grenade launchers. Many armies feel grenade launchers compliment the capabilities of mini-missiles. In many cases grenade rounds are more weight and cost effective than bulkier, heavier and more expensive missiles. Grenades are also more suited to the delivery of less-lethal munitions, being less likely to cause injury than a fast moving rocket propelled projectile. A typical infantry squad will have two members armed with grenade launchers, although this ratio will vary according to tactical requirements. 
Several types of grenade launchers are in common use on the Earth of 2100.
Smart-fusing is standard on suitable grenade launcher rounds. To use smart-fusing the launcher or the weapon it is mounted on must have a suitable fire control system. These are standard on Fifth and Fourth wave battle rifles and common on many other weapon types. Usual fuse options are airburst, impact, delay and “window”. Superquick and timed settings may also be available.
A typical engagement would see the grenadier using his weapon's laser rangefinder to establish the distance to the target. He will usually lase a spot near the target since many systems include laser warning receivers (LWR). These will trigger an alarm and possibly countermeasures if the target is lased directly. The grenadier may also select or modify the range by verbal command or keypad. The next round to be fired is programmed with the desired range. The fire control system will also adjust the sight's aiming mark to allow for range, elevation differences, wind conditions and target movement.
If set to “airburst” the grenade will explode when it reaches the programmed distance. If set to “window” it will explode 1.5 yards beyond the set direction. HEMP rounds used against armour may be programmed to detonate early for improved stand-off effect. Impact is the default setting and will be selected if there is no fire control system or an error in programming.

20mm Launcher.
This weapon has already been described in detail elsewhere. A versatile weapon, its classification poses a problem. As a grenade launcher many of its projectiles have a much higher velocity than is usual for the type. Many of its projectiles are self-propelled micro-missiles cleared from the barrel by a small impeller charge in the case. Whether these projectiles are micro-missiles or small mini-missiles is also debated. With different ammunition the weapon is often employed instead of a shotgun.
These discussions have little relevance to the practical use of the weapon. It is valued as a weapon system that can handle a wide variety of targets.

In addition to the other under-barrel versions of 20mm launchers already detailed there is a self-loading model with a tube magazine. This resembles many late 19th and 20th century firearms in that rounds need to be loaded individually and the last round loaded is the next round fired. Tube magazines should not be confused the magazine tubes used in 30mm grenade pods.
30mm Grenade Pod.
The 30mm grenade pod (aka “GL-pod”) mounts under the barrel of a battle rifle in the same fashion as a mini-missile pod. At a distance the two pods are difficult to distinguish. Like the mini-missile pod the grenade launcher uses the rifle's fire control system to program the grenades. Pods may also be mounted on battlesuits, cybershells or other systems.
The pod contains a short, rifled barrel mounted ahead of a cylinder with three open-sided chambers. Each chamber takes a magazine tube containing three 30mm grenades, all in the same magazine of the same type. The pod can be treated as a weapon with three three-shot magazines. A magazine tube weighs 0.6 lb, a fully-loaded pod 3 lbs. Magazine tubes with different grenade types can be loaded in different chambers. The weapon recognizes the grenade type in each tube and the operator can easily switch between different types.
The magazine tube also serves as the breech of the weapon and uses a superimposed load system. The grenades are arranged and fired in series. Partially-fired tubes can be removed from the weapon and used later. Empty tubes must be returned to the manufacturer or an armourer for reloading. Tubes with high explosive rounds are green with a yellow stripe. Riot control magazines are grey with a red stripe. Smoke magazines are light green with black markings. Canister magazines are black with white markings.
The most commonly used round is HEMP, 6d x 3 (10) cr + linked 2d cr ex [1d+1]. This has the same effects as a TS-era HEMP hand grenade or 30mm warhead. Arming distance is 12 yards. Thermobaric rounds, 8d cr ex, are less common but not unusual. Various types of riot control munitions are widely available and include various gases and thunderflash rounds. Smoke rounds produce an 8 yard radius PFOG cloud for 25 seconds and are mainly used for signalling and target marking rather than screening. Canister rounds are useful for close range operations and contain either buckshot or flechettes.
Average HEMP grenade velocity is 92 yd/s. Range is 560 yds. Homing capability is possible but not typical.

30mm DGL.
The 30mm DGL has some resemblance to the 30mm grenade launcher pod but uses the disposable launch tube technology familiar from 40mm Swift mini-missiles. The tube contains three grenades arranged in series rather than a single mini-missile. One or more tubes can be attached to a rifle or other suitable mounting. If a fire control system is not available the grenades work as “dumb”, impact-fused munitions. Projectiles are effectively identical to those used in the 30mm grenade launcher pod.
Launch tubes may be treated as disposable when in combat. During training used tubes are recycled and reloaded at appropriate facilities.

30mm Individual Grenade Launcher.
The 30mm grenade pod and 30mm DGL are under-barrel launchers that can be fitted to rifles. The 30mm IGL may be thought of as a grenade launcher with an under-barrel rifle! The grenade launcher itself is a semi-automatic weapon with a six or ten round box magazine. Larger, drum magazines may be encountered. The ammunition is derived from that used in the GL-pod and DGL. These, in turn, are derived from contemporary hand grenade and 30mm mini-missile warhead technology. Rather than using a superimposed system the round have more conventional aluminium or polymer cases. Several emag versions of IGLs became available in 2095.
Grenades from a conventional IGL have a similar velocity to those from a GL-pod or DGL, all being designed to produce the same tolerable level of recoil to the user. Emag IGL offer the option of variable grenade velocity. Grenades can be fired at lower velocities for short-ranged high trajectory fire. Velocities of 200-300 yd/s or more allow for flatter, longer range shots, but with corresponding increases in felt recoil. Grenades are also prone to be less accurate if travelling at trans-sonic velocities.
As might be expected, an IGL has all the sighting, range-finding and fire control systems that might be expected for a weapon using smart-fused grenades. IGLs are claimed to be more accurate than GL-pods or DGLs, although some dispute there is a significant difference in actual combat.
Grenade launchers have a relatively long minimum range so many armies fit the IGL with a “kinetic energy” component: a stockless, short-barrelled variant of a battle rifle, BCR or PDW.
The addition of the KE component further increases the weight of the weapon system and reduces its responsiveness in either mode. For rifles the excessively shortened barrel significantly reduces performance. Blast and flash are also a problem with such short barrels. +1 Hearing and +1 Vision to spot a firer in the dark.
Where possible or permitted some users remove the KE component. Others consider the KE component as only for emergencies and reduce the weight of rifle ammunition carried accordingly.