AAI/Colt M203

     Notes:  The M203 was developed during the Vietnam War to replace the M-79 and an earlier experimental underbarrel grenade launcher, the XM148.  The M203 was accepted for service in 1969, and by 2000, almost 300,000 of them had been produced, with the M203 being used by over thirty countries worldwide.  The M203 was an AAI design, and they built the first production batches.  However, even AAI realized that they could not keep up with the even the huge orders from the US military, let alone other countries, and by January of 1970, the M203 was a Colt product; AAI themselves only manufactured 600 M203s.

     The M203 grenade launcher kit consists of a base launcher rail that is attached under the barrel of an M16 or M4-series assault rifle, the barrel and trigger mechanism, a quadrant sight that is attached to the carrying handle of the rifle, a secondary folding leaf sight behind the front sight of the rifle, and a new handguard.  The assembly is very simple and takes less than 5 minutes to attach to the rifle.  Once attached, the M16 or M4 may be used normally, except that a bayonet or the RAW rifle grenade cannot be used, and the sling attaches to the front of the weapon slightly differently (the sling swivel is attached to the side of the front sight base).  The M203 uses a slide action to open the breech, sliding forward for loading, with a latch on the left side of the interface rail being depressed by the thumb of the shooter’s non-firing hand (assuming he is left-handed) being depressed to unlock the barrel.  The round is inserted into the breech, and the barrel slid back again, where it automatically locks into place for firing.  The spent case ejects automatically when the breech is opened again.  The M203 is fired using separate trigger group in front of the magazine well of the rifle to which it is attached; the magazine is used as a sort of pistol grip for the M203.  Inside the trigger guard of the M203 is a safety that looks like a backwards trigger in front of the actual trigger; pushing it forward makes the M203 ready to fire.  When pulled back, the safety blocks the firing pin as well as not providing enough room to put a finger on the trigger.  Construction is primarily of steel, with the special handguard being of one-piece semi-flexible plastic (so that it can be fitted onto the rifle), and a 12-inch aluminum alloy barrel.

     The Colt Launcher System is a development of the M203 into a stand-alone launcher.  It is basically the M203 with a snap-on M16 or M4 stock and pistol grip.  The stock can be removed completely, leaving only the pistol grip, if a more compact weapon is desired.

     The widespread adoption by US forces of the M4 and M4A1 carbines led to the development of the M203A1.  The mounting kit of the M203A1 uses handguards with four-point MIL-STD-1913 rails (borrowed from the SOPMOD kit), assuming the shooter’s carbine does not already have them.  The modified M203A1 (which uses a shorter 9-inch barrel to better fit the M4’s shorter length) can then be easily attached to lower rail of the handguards.  The M203A1 mounting interface also allows it to be easily attached to almost any weapon that has a MIL-STD-1913 rail under the barrel.

     RM Equipment of Miami, Florida also introduced a variant of the M203, called the M203PI EGLM (Enhanced Grenade Launcher Module), in 1987.  (This should not be confused with Colt’s early experiments with an improved M203, also called the M203PI at the time; Colt’s experimental M203PI will be found on the Best Grenade Launchers That Never Were page).  The M203PI EGLM is version of the M203 that is similar to the Colt Launcher System, though it is even more flexible in mounting options and ability to use a variety of accessories. Mounting an M203PI EGLM usually requires very little of no modifications to the weapon upon which it is mounted, though some will require the replacements of their handguards with specially-designed handguards.  The M203PI EGLM may be mounted on its host weapon in one of three ways.

     The Interbar Mounting System (IMC) is a special attachment similar in concept to the original M203, but far more flexible and adaptable in form.  The IMC has the virtue of allowing the M203PI EGLM to be mounted on virtually any rifle, carbine, short-barreled assault rifle, or submachinegun; even a few tactical semiautomatic shotguns are able to mount the M203PI EGLM (in what must be an incredible one-two punch!)  When attached to a host weapon using the IMC, the grenade launcher is on a rock-steady mount. A slight drawback of the IMC is that adding it to a weapon is that it takes more work to attach it or remove it from its host weapon; many host weapons will require the removal of their original handguards and replacement with special handguards incorporating the IMC. (These handguards do, however, generally give the shooter three MIL-STD-1913 rails to use.)

     A second way to mount the M203PI EGLM is by use of the Snap-On Launcher System (SOLA).  The SOLA is a special interbar that can be mounted and removed from the host weapon without any special skills or tools.  This allows the M203PI EGLM to be removed or mounted on many most weapons as necessary, with no modifications to the host weapon required.  The disadvantage of the SOLA is less flexibility when choosing the host weapon to which it is mounted; in general, it will take a rifle somewhere in length between a Colt Commando and a standard M16-series weapon.

     The M203PI EGLM can also be attached to a gripstock, Tactical Mounting System (TMS). This gripstock uses an M4-type collapsible stock that also folds to right to allow the M203PI EGLM to be used as a “grenade pistol.”  The gripstock is equipped with a MIL-STD-1913 rail above the interbar, and a foregrip can also be attached to the barrel of the grenade launcher to improve grip and allow for faster actuating of the barrel when loading and unloading (including a foregrip with an adapter for a tactical flashlight).

     Construction of the M203PI EGLM’s grenade launcher module and most of its associated hardware are of aluminum stock; some other parts of the interbar and TMS may be made from steel or polymer as required. At least 28 countries are using the M203PI EGLM as of late April 2008, including the US.  Weight and barrel lengths for the M203PI EGLM are approximate; I have yet to find any hard information on the proper figures.  (If a reader knows, please let me know.)

     Twilight 2000 Notes: The M203A1 was a rare weapon in the Twilight 2000 timeline, even in US special operations units.  Outside of US hands, the M203A1 is virtually unknown (at least, as an issue weapon).  The M203PI EGLM does not exist in the Twilight 2000 timeline.

Aerojet XM174

     Notes: This was a limited-production, interim grenade launcher meant to be used until more advanced grenade launchers in development were available.  (The XM174 was essentially an advanced prototype, being combat-tested.) It was designed in 1968 in an accelerated design program, and used by US Navy brown-water craft in Vietnam, as well as by certain special ops troops and USAF Security Police.  Some were also mounted on helicopters as door guns.  Though type-designated, the XM174 was never formally adopted by any branch of the US armed forces, and was never used by any other country’s armed forces.

     The XM174 used a modified M1919A6 receiver, with the internal mechanism parts designed for the weapon, and the barrel of an M-79 grenade launcher.  It was fed from an ammunition canister holding 12 rounds and feeding from the left; the rate of fire was such that all 12 rounds could be fired and in the air before the first hit the target.  (The nominal rate of fire was 350 RPM.) The XM174 was also a selective fire weapon, capable of semiautomatic fire.  The grenade launcher was meant primarily to be fired from a tripod or pintle mount, but could also be fired from an attached bipod; however, the bipod was not always supplied with a bipod and they were actually quite rare. Helicopter use was limited by the relatively small ammunition drums, as they were difficult to change in flight. Some handy unit armorers also modified the XM174 to be fired from flexible mounts on the sides of the helicopter; again, the small ammunition drums were a problem, and they were essentially impossible to reload in flight when used on such a mount. Operation was by simple recoil.

Alliant XM25 CDTE

     Notes: This weapon was dubbed the Punisher by troops in Afghanistan who used it.  This was an unofficial name; the more boring actual name of this grenade launcher is the CDTE (Counter-Defilade Target Engagement System), sometimes called the ISABS (Individual AirBurst System).  The XM25 was issued on a limited basis to 10^th Mountain Division and 101^st Air Assault Division troops, who were enthusiastically impressed with its capabilities.  However, the reported malfunctions (primarily with the electronic sights) and 2013 program budget cuts delayed its official entry into service, which was originally scheduled for 2017. The 75^th Rangers in particular were not impressed by the XM25, considering it too prone to malfunction and too bulky and having too small a basic load that their troops can carry without excess weight. They also criticized the need, due to bulkiness, for the shooter to sacrifice his rifle for a pistol. In 2017, the Department of Defense cancelled the contract with ATK, instead deciding to improve the XM25s they already had.  The future of the whole program has been called into question as a result. The XM25, though designed and developed by Alliant Techsystems, is primarily manufactured by Heckler & Koch in their US facilities; the sight system was designed by L-3 IOS Brashear, though it too is primarily manufactured by Heckler & Koch.  Alliant and Brashear are currently working with the Army to improve the XM25’s reliability.  By 2018, development of the XM25 had become a priority program in the US Army’s inventory; the new target date for general fielding is in late 2019.

     . It is designed specifically for the firing of HEAB (High Explosive AirBurst) rounds, which explode over the heads of opponents and essentially negate most of the advantages of any cover the opponents may be using.  It does this with a sophisticated electronic sight system designated the M68 Combat Optic with AN/PEQ-2 Laser/Infrared Aiming Device (what a mouthful!) and programmable rounds (programmed by the sight system). It is, however, of taking direct fire shots, and some other rounds have been developed for XM25, also programmable by the sight system.  The sight system is essentially a minicomputer combined with optical sights which project a special reticule onto the optics.  The sight system also uses a special imaging system to estimate range and direction, and the user can therefore cause the round to explode at the range and height he chooses.  This imaging system uses a laser rangefinder for its calculations. The sight system can also estimate the speed and angle of a moving target such as a vehicle and allow the round to hit.  The sight system is very accurate; in Afghanistan, the sights system usually allowed users to put rounds on targets within about a half-meter of the desired range.  Because of this, scatter for the XM25’s rounds is only one-quarter of normal scatter distance when used for indirect fire. The sight system also has an integral thermal imager. The HEAB rounds are so effective that the US Army is working on a 40mm round with a reduced-size electronic sight.  The sight system has a 4x zoom sight when using its thermal imager, and a 2x direct view optical sight.

     The XM25 uses a semiautomatic, gas-operated firing system.  It is fed by a detachable magazine system.  The normal color is black; however, some have been given an experimental camouflage finish using a pattern identical to the standard Army uniform pattern.  The XM25 is a grenade launcher that is based on the grenade launcher part of the defunct OICW assault rifle.  It is a compact weapon with a bullpup configuration, but surprisingly heavy for its size.  (Much of the surprising heaviness is the electronic sight system and the programmable rounds.) It is normally used with a foregrip, though the foregrip folds if the user does not want to use it.  The rounds are also surprisingly heavy for their smaller caliber, which means that the XM25’s gunner must carry a heavy combat load. Some of the current experimental XM25s use more polymer, advanced aluminum and steel alloys, and a more miniaturized sight system with a 3x direct-fire sight instead of the standard sight’s 2x..  (I have included such an XM25 below for GP.) The sight system used in Afghanistan also had a too-short battery life, and this is another thing that is being worked on to improve.  In Afghanistan, there sometimes double feeds on the XM25; this normally simply jams the XM25, but in 2013, a double feed resulted in a round exploding in the chamber, and the soldier operating it received minor injuries.  This was the direct event that caused the XM25s to be recalled from their combat testing in Afghanistan, even though 5900 rounds had been fired from XM25s before this happened.

     There has been additional combat testing by special operations, particularly by the Army’s Special Forces.  I haven’t been able to find anything regarding their impression of the XM25.

China Lake EX-41

     Notes: This is a magazine-fed pump-action weapon, able to mount a variety of optical and laser sights without damaging the sights.  The weapon fires the 40mm NATO High-Velocity rounds of the Mk-19 automatic grenade launcher.  It was designed by China Lake for the US Navy SEALs, but is still listed as an experimental weapon, and whether or not it has been combat tested is unknown.

     For a brief time, the EX-41 was marketed by Nordac Manufacturing Corporation under the name 40/3 Tactical Assault Grenade Launcher.  I have not been able to find out whether they made any sales.  They do not appear to be selling them now, anyway.

     Twilight 2000 Notes: This experimental magazine-fed grenade launcher was issued in small numbers to US Navy SEALs during the Twilight War. 

     Merc 2000 Notes: This weapon fell prey to budget cuts in the late 1990s.

China Lake Mark 18 Mod 0

     Notes: This Vietnam-era weapon was sort of an oddity to the modern era – it is a hand-cranked belt-fed grenade launcher.  It used a very simple method of operation with few moving parts and simple maintenance.  The ammunition belt was a custom-made Mylar-backed Dacron belt (earlier fiberglass-reinforced tape belts gave too many problems, and they were quickly replaced).  Even the Mylar/Dacron belts were a weak point, good for only about five trips through the Mark 18 before they no longer held the rounds firmly enough, and they too were replaced by cloth belts.  The Mark 18 was produced between 1965 and 1968, and used primarily on small boats or in fixed positions such as bunkers; their primary users were the so-called “River Rats” and the SEALs.  They could be mounted on M-2HB, M-60, or M1919 tripods or pintle mounts, but could not be fired without such a mount. 

     The unusual method of operation of this weapon means that unusual rate of fire rules must be used.  The rate of fire for the Mark 18 Mod 0 in sustained fire operations is one-third the Strength rating of the operator; this may be quickened to one-half the Strength rating of the firer for 20 minutes, or 3/4 the Strength rating of the firer for 10 minutes.  Firing at a normal rate does not count as fatigue, but firing at a rate of fire 1/2 the firer’s strength counts as one level of fatigue, and firing at 3/4 of the firer’s strength counts as two levels of fatigue.  Willpower skill may affect this.  Recoil for “automatic” bursts is equal to 1.5 times the amount of rounds which are fired.

     Some 1200 of these launchers were produced; however, it was never considered as more than a stopgap weapon, to be used until a “real” automatic grenade launcher could be designed and the bugs worked out.  Forerunners of the Mk 19 (below) were already being developed.

China Lake Pump-Action 40mm Grenade Launcher

     Notes: Though never given an official designation by the US military, and never considered more than an advanced prototype, this grenade launcher was one of the best-liked grenade launchers used by special operations troops in Vietnam, especially the SEALs, who reportedly used up to 30 of them in combat.  Army Special Forces managed to get a hold of up to five of them, and the Marines got two of them for use by their Force Recon units.  This weapon resembled a giant short-barreled shotgun, with a tubular magazine below the barrel and the leaf-type sights which were borrowed from the M-79.  The firepower was quite welcome and the SEALs especially had good things to say about the weapon.  The stock was of wood with a thick rubber recoil pad, the barrel and receiver were made from steel, and the magazine tube and pump action were built of aluminum; despite the large size of the weapon, it was fairly light.  Unfortunately, tests and production of this weapon did not continue after the Vietnam War, though lessons from the weapon were incorporated into the EX-41 (see above).

General Dynamics Mark 19 Mod 3

     Notes:  This automatic grenade launcher (often known as the “autoblooper” to troops) was the first practical launcher of its type to be fielded by military force.  The original model, the Mark 19 Mod 0, was designed for use by US Navy patrol boats and SEALs in Vietnam.  It was a spectacular success, well liked by its troops, but mechanically complex and difficult to care for.  A product improvement program began, and the Mod 0 guns were converted to the new Mod 1 specification by 1971, along with new manufacture guns.  The Mod 2 was the first serious attempt to streamline the mechanism of the Mark 19 itself; this was unsuccessful, but the Mod 3 variant was, having 47% fewer parts and being strippable without special tools.  By 2000, over 21,000 Mark 19s had been built for US forces, with many more being made for 22 other countries. 

General Dynamics Mark 47 Mod 0 Striker

     The Striker is an automatic grenade launcher which can be used as a standard AGL, but is specifically designed for use with a fire control computer and a special airburst Programmable Prefragmented High Explosive/Self-Destructing (PP-HE/SD) rounds or HE Airburst (HEAB) rounds which can be programmed by the fire control computer/sight to fire out to a specific distance and explode overhead of dead space, trenches, troops in the open, troops hiding behind walls or in buildings, etc., for the easier elimination of troop concentrations even if they are hiding.  The Striker can also use standard high-velocity automatic grenade launcher ammunition, or use medium-velocity rounds by loading them into the breech individually like a Mark 19 Mod 3 AGL.  The Striker is in essence a highly-modified M-2HB machinegun, which gives it a compact size that is smaller than the Mark 19 and the basic gun is much lighter.  The Striker, like the Mark 19, is however designed to be fired from a tripod (the Mk 108), which weighs 20 kg, versus the 26 kg tripod of the Mk 19. The tripod includes an integral soft mount. The fire control computer/sight is equipped with an integral telescopic day sight and a thermal imager for night use.  The belts are the same as those used on the Mk 19, even when loaded with special ammunition.  The Striker is currently being used by some US special operations forces in Afghanistan, and has apparently been used by them since 2007.  It is currently being evaluated by the rest of the US military as well as Israel.  The basic gun weight below includes the special sight unit/computer.

     The Twilight 2000 Notes: The Striker is not available in the Twilight 2000 timeline.

Manville Gun/MM1 

     Notes:  The original Manville Gun was designed by Charles Manville in 1935.  It was essentially a huge, rotary-cylinder 12-gauge shotgun, with a 24-round capacity contained within a large rotary-cylinder which was wind-up and spring-driven.  Construction was largely of high-strength aluminum (except for a plastic pistol grip, fore-grip, and some other parts which were made from steel, however, the barrels of all versions were made from light alloy, and as might be thought, was large and beastly-heavy.  It has no stock, but was equipped with a fore-grip for control.  Loading was done by releasing two large-headed finger-tight screws at the of the barrel, which allowed the two halves of the Manville gun to be separated; after loading, the reverse procedure was done.  The cylinder was spring-loaded and had to be wound (but in a backward direction from normal).  This gave the Manville gun a light trigger pull, but also (in game terms) adds two phases to the reloading time.  Each chamber of the cylinder was a complete unit, with its own firing pin.  This original 12-gauge Manville Gun had some sales (some would say a surprising amount), but production had stopped by the late 1940s.

     In 1936, Manville also came up with a 26.5mm version of the Manville Gun; this version was nearly identical to the 12-gauge weapon, but used a somewhat simplified construction and the cylinder held 18 rounds instead of the 24 of the 12-gauge Manville gun.  Early models of the 26.5mm Manville Gun used a 9.75-inch barrel, while later versions used a 9.5-inch barrel and were somewhat lighter than the early models.  The later version was much improved in the areas of structural strength and reliability, as well as having more ergonomic pistols grips and foregrips.  Both versions could have inserts put in the barrels and cylinders to allow the use of 12 Gauge and .38 Special ammunition (though these ammunition types could not be mixed, since they involved a barrel insert as well as cylinder inserts). 

     Late in the 1930s, Manville created a version of the Manville Gun which could fire the newly-available 37mm grenades.  This version had a 12-round capacity and the mechanism was effectively upside-down with the barrel at the bottom of the cylinder.  The 37mm Manville gun was intended to be fired like a repeating mortar under normal circumstances, though it could be fired by one man if he were strong enough to manage the enormous weight.  It could also be mounted on the tripods and pintle mounts of the time.  Construction was otherwise the same as the late version of the 26.5mm Manville gun, but there were no barrel and cylinder inserts.

     The military and police showed little interest in any version of the Manville Guns, but the Manville Company survived World War 2 by building antiaircraft guns, gun parts for existing large-caliber guns, and – believe it or not – dishwashers!  In 1943, Manville gave up on the Manville guns, ordering the destruction of the production machinery, dies, and most of his notes.

     The late-model 26.5mm Manville Gun was used in the movie Dogs of War, called the “XM18E1R” in the movie, though the effects seen in the movie were far greater than an actual 26.5mm Manville Gun was capable of producing.  Alert viewers of the movie will notice that the catalogue that Christopher Walken’s character was perusing in the movie included a round called the “Flashette.” It is believed that the writers actually meant “Flechette” (though this is not certain; the writers have not said what they actually meant). Regardless, Flechette rounds were never actually developed for the 26.5mm Manville Gun or the 26.5mm MM1.  However, I have included it below as a “what-if.”

     Ironically, Dogs of War created a new interest in the Manville Gun in the late 1970s.  At first, these launchers were built by Hawk engineering, but this quickly passed to the Frankford Arsenal, who decided to renew the production of the 37mm Manville gun using new production methods and materials, calling it the MM1.  Later, Frankford made 12-gauge, 26.5mm, and 40mm versions of the MM1.  These “new” versions of the Manville Gun are far lighter than the originals.  Unfortunately, the MM1 also enjoyed few sales, and though Frankford Arsenal will still make them upon request, they are no longer mass-produced. The US and some NATO countries reportedly have some 40mm versions for use by special ops troops.

     Twilight 2000 Notes: Ironically, the Twilight War renewed interest in the Manville Gun and MM1, particularly in the 26.5mm and 40mm versions, and Frankford Arsenal was asked by the Pentagon to greatly step production of the MM1, particularly in those two calibers.

Milkor USA M32

     Notes: Produced by Milkor USA (a subsidiary or South Africa’s Milkor Defence), the M32 is a modified form of the Milkor MGL Mark 1 (more commonly known as the MGL-40 or MGL-140).  So far, the M32 is used only by US Marines, though reportedly other branches of the US military, as well as a few other countries, are evaluating or considering buying the M32.  The Marines were combat-testing the M32 since 2004, with official adoption taking place in 2005. 

     As with the MGL Mark 1, the M32 uses a single barrel, fed by a 6-round revolving cylinder.  The rear part of the M32, consisting of most of the gripstock and the rear plate of the cylinders, swings away from the rest of the M32 for loading.  The spring-loaded cylinders are wound with a knob at the front of the cylinder (taking two actions), and then the M32 is locked back together.  In addition to the spring-loading, the M32’s cylinder is gas-actuated.  The cylinders rotate as a revolver, but the shooter can use a manual override in order to skip over dud rounds.  This feature also allows the shooter to have different types of ammunition loaded into the cylinders, and choose which type of round he wishes to fire.  The trigger is double-action-only; while this virtually eliminates the chances of an accidental trigger pull, it also makes the trigger pull very heavy. Barrel length is 14 inches.

     There are a number of differences between the MGL Mark 1 and the M32.  The M32 uses four MIL-STD-1913 rails instead of the single proprietary sight mount of the MGL Mark 1; these rails are atop the receiver/barrel and on the sides and bottom of the barrel, with the barrel being partially surrounded with a handguard for this purpose.  (The Marines normally use a detachable handgrip on the lower rail.)  The Armson Occluded-Eye Gunsight of the MGL Mark 1 is replaced by a Milkor M1A2 reflex sight designed for Milkor by a South African company called Green Trading; this sight is an adjustable reflex sight with a slight magnification, and has an illuminated quadrant grid reticle to assist in aiming.  The cylinders of the M32 are longer; this allows the shooter to use almost the entire inventory of 40x46mm rounds (any round 140mm or less in length), including most pyrotechnics, flares, star shells, and some upcoming advanced rounds.  The folding stock of the MGL Mark 1 is replaced with a stock similar M4 Carbine-type stock; made by Vltor, this stock has six sliding positions, has limited adjustment for the angle of the stock, and has a thick recoil pad.  The M32 is also finished in Gunkote SCK6, which is highly resistant to corrosion and wear.

     MKEK in Turkey produces a near-copy of the M32.  For the most part it is the same.  Differences are noted Below.

     Rippel Effect (the new name of Milkor as of 2010) now markets the M32 on the general world arms market, calling it the XRGL-40 (Extended-Range Grenade Launcher, 40mm).  Their collaboration with the US Marines appears to have served them well.

     Twilight 2000 Notes: The M32 is not available in the Twilight 2000 timeline.

Naval Ordnance Station Mark 20 Mod 0

     Notes: The Mark 20 was designed by the Naval Ordnance Station in Louisville, Kentucky to address the biggest problem with the Mark 18 crank-operated grenade launcher – the crank-operation.  The Mark 20 was perhaps the first grenade machinegun, and is a selective fire weapon with the low rate of automatic fire which became characteristic of most automatic grenade launchers in the future.  Prototypes were available by 1967, and the weapon received its military designation and began combat use in 1968.  The Mark 20 uses a rather peculiar method of operation – blow-forward combined with recoil operation.  When the Mark 20 is cocked, the barrel is actually pushed forward; the barrel snaps back around the 40mm round when the trigger in the spade grips is pushed.  The force of the grenade moving down the barrel moves the barrel forward again, which causes the weapon to be recocked.  The bolt, on the other hand, flies back from the recoil and completes the cycle.  Though this method of operation means that the weapon has little felt recoil, it is also a very complicated method of operation.  The Mark 20 is designed to be fired from pintle or tripod (NLT or NHT) mounts, but it can actually be fired handheld in short bursts.  (The designers had intentions to develop the Mark 20 into a version with a standard stock, trigger, and bipod, but this was never done.)  The Mark 20 is fed by disintegrating-link belts.  Some 1080 of these weapons were built by 1971, when production ended, replaced by the then-new Mark 19 Mod 0 (see above).

Philco-Ford XM129

     Notes: This was an early aircraft grenade launcher system which can also be used in ground-mounted installations.  It was originally designed for use on the AH-56 Cheyenne attack helicopter prototype.  The XM129 is externally powered, either from the helicopter in which it is installed or by an attached battery or generator.  The XM129 was also made in a rare hand-cranked system; A Vietnam-era weapon, it was rare and normally used by riverboats and the occasional vehicle.

     The hand-cranked version has special rules; the ROF of the XM129 is at a rate of one-third the Strength rating of the operator. This may be quickened to one-half the Strength rating of the firer for 20 minutes, or 3/4 the Strength rating of the firer for 10 minutes.  Firing at a normal rate does not count as fatigue, but firing at a rate of fire 1/2 the firer’s strength counts as one level of fatigue, and firing at 3/4 of the firer’s strength counts as two levels of fatigue.  Willpower skill may affect this. The ROF below is for the helicopter or motor-driven system.  When ground-mounted, the XM129 is fired from the same tripod as the M-2HB machinegun.  The barrel reciprocates with every round fired.  The XM129 can be assembled to feed from either the left or right side, and the weapon is designed so that the center of gravity reduces the recoil. The stats below are for the ground-mounted system, fired by a motor.

Sage Industries Deuce

     Notes: Sage has long been a participant in the design or outright manufacture of small arms, heavy weapons, and modification parts for weapons.  Surprisingly, their name appears on few complete weapons, because they tend to make parts and aftermarket parts for weapons instead of designing a weapon from the ground up.  One of these is the Deuce grenade launcher.  Some might look at a Deuce and say, “It’s just two M203s or M320s stuck together.”  They are only in a rather remote sense correct; the Deuce does consist of a pair of grenade launcher mounted over-and-under. However, this is only an external appearance; Sage has built the Deuce from the ground up.  Development of the Deuce began in 2009, and it was first shown at the 2011 SHOT Show; the design is currently a mature design, lacking only in buyers.  However, though some military units worldwide are interested, the primary interest has come from police organizations, for the 37mm launcher, which is designed for use only with non-lethal ammunition.

     The Deuce is little heavier and bulkier than the average assault rifle (and reloads are heavier); however, the Deuce is not designed to and cannot be mounted under a rifle or other weapon.  The Deuce is designed based on a DoD study in early 2008, which state simply that the average grenadier requires 1.4 grenades to achieve virtually all targets it may be fired at. The Deuce is a rugged design, made of mostly light alloys and polymers except for the rearward section of the barrel, and some other parts which might be under greater stresses.

These are made of high-strength carbon steel.  Reliability of the Deuce is high due to its simple construction (its primary moving parts are to open the breeches, adjust the iron sights, and in the firing mechanism and sliding stock).

     The standard Deuce G-1 fires standard 40x46mm grenades, though it can also fire the 40x51mm ERLP rounds as well.  Loading and unloading is done by break-action; the weapon opens 90 degrees to load ammunition.  Safety was design in, with a crossblock trigger safety, a manual striker lock, and an internal safety to prevent the Deuce from firing accidentally if bumped or dropped.  Barrel selection is done via a large lever on either side behind the barrels.  The Deuce G-1 (and other Deuces) are finished with phosphating, anodizing, and a black weather-resistant outer finish.  The barrels are 12 inches long, and sights consist of two flip-up rear sights (the front has one for up 20-40 meters, and one for 40 meters out to extreme range). 

     The rear sight has a calibrated flip-up ghost ring aperture.  Above the receiver as well as along the length of the top barrel are MIL-STD-1913 rails.  About a quarter-length back, there is a very short rail.  A further rail can be locked into the rail above the barrels if necessary.  The receiver is made mostly from a single light alloy machining, though the trigger pack is in the receiver and accessed through a plate on the right side. At the rear of the receiver are attachment points for a sling; under the front MIL-STD-1913 rail are further attachments for a sling.  The rear sling points have two slots, allowing the weapons to be carried with a one-point assault sling.  The stock and pistol grip are Magpul-made; the stock is a sliding stock and has six positions, but is lighter than the standard M4-type stock.

     The Deuce G-2  for the most part, it is the same weapon as the Deuce G-1; however, the Deuce G-2 has no sling swivels and is restricted to 37mm rounds, most of which are less-than-lethal.  In addition, the Deuce G-2 is equipped with 14-inch barrels instead of the 12-inch barrels of the Deuce 1.  The barrels are rifled (in both cases), allowing the Deuce G-2 to fire standard 37mm smoothbore rounds, rifled rounds, or the newer Arwen 37 rounds.

TRW M-79 

     Notes:  Perhaps the first such weapon introduced into regular military service in any sort of large numbers, the M-79 was first issued to US military units in small numbers in December of 1959.  A number of bugs arose during initial service use (particularly regarding the overly-complicated sight used in early production models and premature barrel wear) meant that large scale production and issue did not begin until about 1962.  The original design and production was done by TRW, though production was quickly subcontracted to a number of manufacturers in the US. The M-79 figured prominently during the Vietnam War, and is still in use worldwide; many countries still produce them (with and without a license) and some have designed improved versions. Use has spread from military forces to police forces in some cases.  Although replaced in many countries by newer grenade launchers, the M-79 is favored in many countries due to its ease of maintenance and use, as well as being rather inexpensive and easy to build (and quite available on the world market).  The M-79 (known as the thumper, blooper, thump gun, bloop tube, etc.) uses NATO standard 40x46mm low-velocity grenades; it was the first weapon to fire these grenades.

     The M-79 is simple in construction, being little more than a wooden stock with a thick recoil pad, a steel receiver, an aircraft-quality 14-inch aluminum barrel, and a thin wooden handguard.  The folding rear sight is a tall, ladder-type leaf sight, with a notch that moves up and down the light assembly to adjust for range as well as back and forth to adjust for windage.  For direct fire, the sights are folded down, with a secondary rear notch sight (built into the primary sight) and a high front blade used for aiming.  (In practice, firing the M-79 actually calls for a lot of practice, skill, and “Kentucky windage.”).  For loading, the M-79 breaks open like a single-shot shotgun or rifle; though it’s a simple procedure, this can make reloading slow, especially in the hands of an inexperienced gunner.  There is a huge variety of 40x46mm low-velocity grenade ammunition available, though this is simplified (perhaps overly so) in the Twilight 2000 v2.2 rules.

     In Vietnam, US troops would sometimes cut the barrel of the M-79 to shorter lengths to make it handier (this was especially common among special operations troops).  These chopped lengths could be as much as half the barrel or more, making it into sort of a grenade pistol.  Before the introduction of the M203, M-79s were sometimes seen with both chopped barrel, sights removed,  and the stock greatly abbreviated, and the entire affair attached as best possible underneath the handguard of an M16.  These alternate barrel lengths and installations are not noted in the charts below, since they were so variable.  Another interesting note, one that probably wouldn’t have any bearing on a Twilight 2000 game: dummy training rounds made for use in the M-79 will not fit into an M203; in an M203, those M-79 dummy rounds will get tightly stuck in an M203, and they are very difficult to force back out.

XM148

     Notes: This predecessor of the M203 was developed to combine the firepower of the M16A1 assault rifle and the M-79 grenade launcher into one package.  Prior to this, soldiers would sometimes cut off the stocks and remove the sights of their M-79s and crudely wire them to the handguards of their M16s and CAR-15s.  Also known as the CGL-4 (Colt Grenade Launcher 4, the Colt designation for the weapon), the XM148 was, like the later M203, a single-shot grenade launcher designed to be hard-mounted to a standard M16 or CAR-15.  The XM148 has a small, half-length pistol grip below its barrel; this served to open and close the breech.  Once loaded, a large knob on the rear of the receiver was drawn back to cock the weapon.  A trigger bar extended from the right side of the XM148, ending just in front of the M16 or CAR-15.  The trigger bar contained a trigger which was rotated downward; this took the weapon off safe and readied it to be fired.  The operator did not have to take his hand off the M16’s pistol grip to fire the XM148.

     While soldiers liked the added firepower, the XM148, being essentially a developmental weapon, had a number of flaws.  The XM148 was a rather fragile weapon, and used a lot of parts in order to function.  The trigger bar was essentially unprotected, and if branches, equipment, fingers, etc., accidentally bent the trigger bar, it would jam the weapon and make it unable to be fired.  It could also get hung up on things, especially in the jungles of Vietnam.  The unprotected trigger, if extended for firing, could cause the XM148 to go off accidentally if it got caught up on something, especially since troops tended to carry the M16/XM148 loaded and cocked.  The weapon could also be fired by pressing on the sear bar even if the XM148’s trigger was not extended.  The safety mechanism was, therefore, unreliable.  When first M203s became available in 1969, the XM148s were replaced in short order by the new weapon, and XM148s were destroyed, relegated to museums or collectors, or kept in various military arms facilities.