Notes: This is a bullpup version of the various AK-series weapons, generally sold as a kit to convert existing AKs rather than a full weapon. It was not a Russian weapon, but instead was sold in the US and Europe, as well as some other parts of the world, by a couple of American companies. It was one of the few bullpup rifles available to the general public before the war, most bullpup weapon being produced exclusively for military and police forces. The conversion from standard AK to AKU-94 configuration takes about 2 hours and takes an Easy: Gunsmith or Difficult: Small Arms (Rifle) roll. The resulting weapon is over 25 centimeters shorter, but has a creepier trigger pull. In addition, the construction of the AKU-94 is such that left-handed firers tend to have the charging handle hitting their face during firing, so it is definitely a right-handed weapon. The new weapon is also not as well balanced as a standard AK.

Twilight 2000 Notes: Though there were some reports of Russian and Chinese troops using these weapons, the reports of Russians using them are probably misidentified OTs-14s, and the Chinese weapons were probably locally-manufactured weapons of similar design and characteristics. Though there were some civilians who had this modification done to their weapons, the AKU-94 was never a widely-used weapon, and most of them were made from AK-47s or AKMs. There were most likely almost no conversions of AKMRs to this standard, but such a modification will exist only in the Twilight 2000 world.

Merc 2000 Notes: This is mainly just a novelty type of conversion.

Notes: This is basically an AR-15 carbine modified to fire 5.45mm Kalashnikov ammunition (which Alexander Arms calls the .21 Genghis round; Alexander Arms’ round does differ in several ways from the 5.45mm Kalashnikov, but not in any way that can be simulated with Twilight 2000 game mechanics). The Genghis features a 16-inch barrel; it is not typically equipped with a flash suppressor, being designed primarily for the civilian market, but does have a MIL-STD-1913 rail instead of a carrying handle, and is built to otherwise meet or exceed military and police specifications. (Versions with carrying handles instead of MIL-STD-1913 rails are also available.) Ten-round magazines are normally supplied with the Genghis, but modified AR-15/M-16 magazines with larger capacities are also available.

Twilight 2000 Notes: This rifle is not available in the Twilight 2000 timeline.

Armalite AR-18

Notes: This weapon was designed in the 1970s with experience gained from the M-16 series. Armalite found that there were a lot of countries that wanted to license-produce the M-16, but did not have the modern facilities required to produce the more complicated M-16. The AR-18 was designed to be simple and cheap to produce, as well as being relatively "soldier-proof." The US Army tested it, but did not produce it; it was then licensed to Howa Machinery in Japan, NWM in the Netherlands, and Sterling in Great Britain. They also got virtually no military contracts, and Sterling sold its license to a company in the Philippines (who also got no military sales). Much more lucrative was a semiautomatic civilian version, the AR-180; tens of thousands of AR-180s were sold to civilians in various countries. The AR-18S is a shortened AR-18, similar in concept to the CAR-15. Bayonets and rifle grenades can be used, if the flash suppressor is removed.

A later civilian version, the AR-180B, is somewhat different than the standard AR-180 and bears some elaboration. The AR-180B uses a lower receiver made from polymer strengthened with a steel liner. The shape of this lower receiver mimics the original lower receiver exactly, so that an upper of an AR-180 may be placed on a lower from an AR-180B and vice versa. The trigger group of the AR-180B is borrowed from the AR-15 instead of being the original AR-180 design. The front and rear sights are also borrowed from the AR-15A2, though the protective ears are different from those of the AR-15A2, and there is no elevation adjustment wheel on the AR-180B (elevation adjustments are done on the front sight). The scope mount is of original AR-180 design. There is a new design magazine well which allows the use of AR-15, M-16, and AR-18 magazines. The magazine release button is thus the same as on an AR-15, and there is a small protrusion to prevent its being pressed accidentally. The AR-15 has a sort of "half-pepperpot" muzzle brake instead of the original flash suppressor. The barrel is slightly longer at 19 inches.

Twilight 2000 Notes: Starting in 1995, production of military AR-18s started again in the Philippines and Great Britain, who managed to sell a large amount of them to African and Southeast Asian countries. Sterling later produced more for issue to local militia units loyal to the Crown. NWM in the Netherlands also produced some AR-18s, and they were used by Dutch and Luxembourg resistance fighters against the French. In the US, many as Russian or Mexican soldier (or sometimes, Milgov, CivGov, or New American soldier) discovered that their enemy was a local militia soldier armed with an AR-180 or AR-180B converted to automatic fire.

Merc 2000 Notes: This was surprisingly common in issue to people working for US or British intelligence, due to the problem with tracking down exactly who made the weapon, and the ease with which its parts could be made.

Notes: The M-15 is essentially a modernized version of the AR-15, and may also be regarded to some extent as a smaller version of Armalite’s New AR-10 Series. The M-15 comes in four basic versions: the M-15A2, basically very similar to the AR-15A2, but with a heavy barrel, muzzle brake, carrying handle a la AR-15, and round handguards and a stock similar to those of the AR-15A2. The standard barrel is 20 inches, but there is also a carbine version with a 16-inch barrel. The M-15A4 is basically the same weapon as the M-15A2, but uses a flattop upper receiver with a MIL-STD-1913 rail. The M-15A4 is meant to be used with various optics, but there is a very short MIL-STD-1913 rail in front of the handguards, and iron sights may be attached to the two rails. The A-15A4 is a little lighter than the M-15A2. The M-15A4(T) is a target version of the M-15A4; the rifle version uses a 24-inch heavy barrel which is target crowned and designed for accuracy, and it has no muzzle brake or flash suppressor. The upper receiver is flattop and has a MIL-STD-1913 rail, and the handguards are round and made from aluminum. There is also a carbine version of this weapon; this has the heavy target barrel, but it does have a muzzle brake and the barrel is only 16 inches. The trigger of these two versions is a National Match two-stage trigger. The M-15A2 and A-4 Carbines are special models designed for military and police use; they may have automatic fire capability as options, use an M-4-style folding stock, and may have a 14.5-inch or 16-inch barrel with a flash suppressor instead of a muzzle brake. The M-15A4 LE Carbine is flattop; the M-15A2 LE Carbine has a carrying handle.

Notes: The idea behind this weapon was to produce a compact version of the M-16 while avoiding the massive muzzle blast and firing signature that such a weapon normally produces. To this end, Arms Tech used a standard M-16 lower receiver and paired it with a modified upper receiver using a specially designed barrel shroud/muzzle brake. The standard buttstock was replaced with a sliding wire stock, and the carrying handle was replaced with a MIL-STD-1913 rail (the stock Compak-16 comes with an Occluded Eye Sight licensed-produced from a South African design). The cyclic rate has also been reduced to 600 rpm (though this has no effect game-wise). The rifling allows for the effective use of either SS-109-type or M-193-type ammunition, as well as subsonic rounds. Arms Tech has also designed a silencer for use with the Compak-16, which is easily attached and removed, as well as one which replaces the barrel assembly and becomes an integral part of the Compak-16.

Twilight 2000 Notes: Though it had little success with the military or police, survivalists and militia members in the US liked the Compak-16, especially female members.

Merc 2000 Notes: This is mostly a civilian niche weapon, though there has been some experimentation by the US military, the CIA, and various Federal agencies.

Notes: The M-1 Carbine was designed in response to a 1940 US Army request for a weapon to replace the pistol and submachinegun in rear area troops. However, a lot of M-1 Carbines were actually used by infantry leadership personnel, paratroopers, commanders, and suchlike; it was modified, reworked, and put into uses far different than it’s intended role as a weapon for support troops. It continued in service until well into the Vietnam War, where it was often issued to ARVN troops and strikers working for US Army Special Forces. Before military production stopped, almost 6.5 million of them had been built in the US and Italy (by Beretta). M-1 Carbines are still in use in 2005; they were sold and given away by the US government to civilians, bought by police departments, and given to Third World armies supporting the US cause during the Cold War. There are still some civilian arms companies manufacturing the M-1 in small numbers, and they also have been modified for many different calibers by both manufacturers and individual weaponsmiths.

There were four variants of the M-1 Carbine built by the US government: the basic M-1, a standard format rifle; the M-1A1, an M-1 with a folding metal stock built for World War 2 paratroopers; the M-2, a selective-fire version of the M-1; and the M-3, an M-1 built specifically to mount the then-new IR sniper scopes being experimented with at the end of World War 2. (Only 2100 M-3’s were made, and most of them were converted back to the M-1 specification later.)

In 2005, Auto-Ordnance began making a new version of the M-1 Carbine, and later introduced three other versions. Their version, the AOM-130, is not an exact reproduction; the stock is of stained birch instead of the linseed oil-finished walnut of the original version. The Auto-Ordnance Carbine has some later M-2-style features, such as a safety which consists of a rotary switch instead of a crossbolt safety; an M-2 style bolt instead of the original "flat" bolt (though it does not contain an auto sear); the rear sight is of the improved M-2 variety; the front sight is protected instead of being open; and the weapon has a bayonet lug. Furthermore, the rear sight is more adjustable than the standard M-2 sight. There is also a slight weight difference; the Auto-Ordnance M-1 Carbine is heavier than the standard M-1 Carbine. The AOM-130 is shipped with 15-round magazines, but can also take 30-round magazines (if you can find one). The AOM-140 is identical, except for a modification that allows it to take only a 10-rund magazine specially designed for it; it is designed for sale in California. The 10-round magazine will not fit in any other of the new Auto-Ordnance M-1 Carbine versions. For game purposes, it is otherwise identical to the AOM-130.

The other versions are the AOM-150, which is a copy of the M-1A1 folding-stock version; again, there is a weight difference, and the AOM-150 has the same modifications as the AOM-130. The AOM-160 is a sort of modern version of the M-1 Carbine; it has black polymer furniture, a black oxide finish on the external metalwork, and a side-folding polymer stock mounted on a steel frame. The polymer of the pistol grip is rubber-coated and checkered, and has a small finger stop at the bottom. The barrel shroud is steel and perforated for cooling (though I wouldn’t think it would really be necessary). Despite all the polymer, it is the heaviest of the new Auto-Ordinance M-1 Carbines.

Twilight 2000 Notes: The Auto-Ordnance versions of the M-1 Carbine are not available in the Twilight 2000 timeline.

Notes: This modification of the M-16/M-4 series was designed specifically for use by US special operations forces. The weapon was initially tested in very limited quantities in Afghanistan starting in 2002, and some are also being used in Iraq. The M-468 is essentially a stock M-4 or M-16 lower receiver with a new upper receiver and barrel designed by Barrett, and firing new ammunition designed by Remington. The new upper receiver has a bolt carrier group designed for the new cartridge, and the weapon is fed from modified M-16-style magazines. The upper receiver is fitted with a MIL-STD-1913 rail in lieu of a carrying handle, there are four further such rails on the handguard, which is similar to that of the M-4 SOPMOD. Folding iron sights are fitted to allow clear use of optics and accessories.

Recently, a version with a short 12.5" barrel and the capability to mount a suppressor has been designed. This version is primarily aimed at military users (particularly special operations), and a civilian version is not planned, as the barrel is too short for legal civilian sales in the US. In this version, the muzzle brake is much more beefy, and a sliding stock is standard.

The model number "468" refers to the year 2004 (the official date of entry into military stocks) and the caliber (6.8mm). Barrett also has plans to produce a semiautomatic version for civilian use, without all the bells and whistles.

In 2008, Barrett released the REC-7 (Reliability Enhanced Carbine, designed in 2007) carbine. This is essentially an M-468 with the operation changed to use a gas piston system instead of a straight Stoner-type gas impingement system. More of the key components are of stainless steel, particularly the innards. The gas regulator is adjustable, allowing for the removal of the flash suppressor and attachment of a silencer. The iron sights are folding types. Barrel length is 16 inches, with a heavy barrel. The stock is an M-4-type sliding stock.

Twilight 2000 Notes: This weapon does not exist in the Twilight 2000 timeline.

Notes: Introduced in 2004, this is a truly weird small-caliber weapon: a belt-fed, rimfire carbine. It is normally only available in semiautomatic form, but an automatic version is available to Class III dealers or police, military or certain government agencies. Currently, the stocks are made of laminated walnut, but other stock options are promised for the future. The BF1 can take clip-on and bolt-on bipods without modification, but a bipod is not provided as standard equipment. The sights are a proprietary design and consist of a combination of a post rear sight and a front sight called a "spade" (due it’s shape being reminiscent of a spade in a deck of playing cards). This system helps cut down on target obstruction from the sights themselves. Current BF1’s are chambered for .22 Long Rifle and .17 Mach 2 Rimfire, but in the future, Eric Graetz (the designer) plans to chamber the weapon for .22 Winchester Magnum Rimfire and .17 Hornady Magnum Rimfire.

Twilight 2000 Notes: This weapon does not exist in the Twilight 2000 timeline.

Notes: This has been described as an improvement over the original Carbon-15 by Professional Ordnance. (Bushmaster acquired the Carbon-15 after Professional Ordnance declared bankruptcy in 2002.) It is, in appearance and operation, quite different from the AR-15, from the lightened stock to the "miniaturized" bolt carrier group. The biggest difference is the use of light carbon-fiber construction in the new stock, handguards, and even the upper and lower receiver housings. The bolt carrier group is much shorter than the standard AR-15 bolt carrier group due to the deletion of the forward assist; it is felt by Bushmaster that its Carbon-15 design, together with improvements in ammunition, make the forward assist unnecessary. The selector controls are ambidextrous. The Carbon-15 uses a flattop receiver; a MIL-STD-1913 rail extends from the rear of the upper receiver to the end of the handguards. The barrel is heavy, but made of lighter alloys and is fluted, further driving down the weight without compromising accuracy. The Carbon-15 has a new muzzle brake that is extremely effective, actually driving the barrel down when firing. At present, the Carbon-15 is available only in a semiautomatic version, but an automatic version is contemplated for the future for law enforcement and military use.

A post-ban variant of the Carbon-15, the C-15M4 (Carbon-15 Model 4) is an M-4-style Carbon-15 which still has the carbon-fiber upper and lower receiver and handguards, but there is also a partially-synthetic collapsible stock. The barrel is similar to that of the standard Carbon-15, but is not fluted. Unlike the Carbon-15, the C-15M4 will accept standard M-16/AR-15/M-4 parts. The C-15M4 uses standard AR-15/M-16/M-4 magazines; automatic versions are sold only to military or law enforcement concerns. Another post-ban variant of the Carbon-15 is the Carbon-15 in 9mm Parabellum; this version is basically a C-15M4 rechambered for 9mm, with appropriate changes in the sights. Though technically a submachinegun instead of an assault rifle, it is included here for completeness.

Twilight 2000 Notes: This weapon does not exist in the Twilight 2000 timeline.

Notes: This weapon was originally designed in Australia by a company named Edenpine, and meant for sale on the civilian market. Edenpine realized that Australia’s rather restrictive civilian firearms laws would severely limit its sales in that country; therefore, Edenpine reached an agreement that Bushmaster would build and sell the M-17S under the Bushmaster name, with Edenpine receiving royalties from each sale as well as money from the licensing of the design.

The M-17S is basically a bullpup version of the AR-18 in a semiautomatic version. The Bushmaster company made no apologies for the fact that it would use any magazine that would fit in the AR-18, AR-15, or M-16 series, nor the fact that it could be very easily converted to automatic fire. The operating parts of the M-17S are largely made from stainless or chrome-plated steel, with the upper receiver being made almost entirely of a single aircraft-grade aluminum extrusion and the lower receiver from fiberglass-filled nylon composites. Because of the bullpup layout, Bushmaster was able to lengthen the barrel to 21.5 inches, giving the M-17S greater accuracy than most assault rifles. The M-17S has a carrying handle topped with a MIL-STD-1913 rail. The M-17S is specifically meant for use with optical sights or other aiming accessories, but it does have rudimentary backup iron sights. The M-17S is no longer in production, but when it was, it was primarily built as a semiautomatic rifle, with a flash suppressor for police/military use or without one for civilian sales. (Rumors state that a small number were also built with automatic fire capability, but this is not confirmed. I have included stats below for automatic fire just in case.)

Twilight 2000 Notes: There was some limited military and police use, but this was mostly a weapon used by civilians and militia forces. Most were found in the US, but some were also found in the UK.

Notes: The Dissipator is a carbine variant of the M-16A2 that uses standard-length M-16A2 handguards and a front sight placed further forward than most carbine variants of the M-16A2. This means that despite the shorter length, the sight radius is almost identical to the standard M-16A2, which allows a little better accuracy. It also allows better dissipation of heat than a normal M-16A2 carbine (hence the name), and means that the Dissipator can mount the M-203 using a standard M-16 interface rather than having to have a custom-made interface.

Other versions of the Dissipator include the Shorty, which has a fixed stock, the Target Model, which is almost identical to the M-16A3 and A4 except for the burst/automatic selector, and semiautomatic-only versions of the weapon for civilian use (these do not have flash suppressors or bayonet lugs, and cost $6 less than their military counterparts). Other than civilian sales, the only large-scale users of the Dissipator series as of 2002 were the US Department of Energy.

Twilight 2000 Notes: As the Twilight War intensified, the US company of Bushmaster became, along with Colt, Armalite, and a few other companies, a major supplier of M-16 series weapons to the US military and its allies. (Some US soldiers were actually equipped with the Dissipator Target Model instead of the M-16A3 or A4.) They did not have much luck with the Dissipator before the war, but as Bushmaster was one of the weapons manufacturers that survived the November Nuclear Strikes, the MilGov asked them to distribute some of their Dissipator Carbines to some of the militia units formed in the aftermath of the nuclear strikes. MilGov thought the carbine would be especially suited to female militia members, and some of the younger members (some militia members were as young as 12 in some places). Bushmaster complied and even manufactured a limited extra quantity, hampered only by irregular supplies of raw materials.

Merc 2000 Notes: As the Notes, except that the Dissipator is also routinely supplied to CIA-equipped mercenaries.

Notes: This is basically an M-16 with a collapsible stock, shorter barrel, and otherwise made as light as possible and still maintain the tactical utility of an M-4. The handguards have 4-way MIL-STD-1913 rails to allow the mounting of as wide a variety of accessories as possible; there is another MIL-STD-1913 rail on top of the receiver, which does not have the usual carrying handle. There are two versions; the military model, as described, and the civilian model, which is semiautomatic only, has no flash suppressor or bayonet lug, and does not have the special handguards.

Twilight 2000 Notes: This weapon does not exist in the Twilight 2000 timeline.

The CAV-15 is an unusual sort of M-4/M-16 clone; the lower receiver, stock, and pistol grip, are made of one piece of composite material, specifically Nylon 6 filled with glass fiber. The handguards are made of the same material. This material is very strong and totally resistant to corrosion. It can also be molded in virtually any color and even to a specific shape if the user is willing to pay, allowing for cheekpieces, individual hand shapes and sizes, etc. The manufacturer, Cavalry Arms, offers a lifetime guarantee on the lower receiver and handguards that they will not break. The company makes the composite components in several different colors: black, green, tan, and even yellow, blue, and pink. The usual M-16/M-4 carrying handle is eschewed in favor of a flat top with a MIL-STD-1913 rail. Four models are available: the Commando, a military carbine not available to civilians; the Trooper, a civilianized Commando; the Scout, a semiautomatic carbine with a longer barrel; and the Rifleman, a full-sized rifle.

Twilight 2000 Notes: This weapon does not exist in the Twilight 2000 timeline.

Colt M-4

Notes: This is a cut down version of the M-16A2, as a CAR-15 is a shortened M-16A1. This weapon, unlike the CAR-15, can mount the M-203. The weapon was designed for paratroopers, to allow them to jump with their weapon uncased (for faster access during combat jumps), but is becoming the standard assault rifle in many other types of US units as well. The British SAS and SBS also use a large amount of M-4s, particularly the M-4 SOPMOD. The M-4A1 is the same weapon, but fires fully automatic instead of 3-round bursts. The SOPMOD (Special Operations Modification) M-4 is a further development of the M-4A1, with the carrying handle removed and replaced by a Picatinny Rail to allow the mounting of a wide variety of sights and visual aids. Another Picatinny Rail may be mounted under the handguard, to allow even more sights to be used simultaneously (such as an infrared sight on top and an infrared pointer on the bottom); alternatively a foregrip, grenade launcher, or modified shotgun may be used. (The type of accessories a SOPMOD M-4 may use is so wide as to be limited only by the imagination of armorers; in game terms, the player who is equipped with an M-4 SOPMOD may choose up to $300 of accessories for his rifle, and these are included in the cost.)

Twilight 2000 Notes: Airborne, special ops, and some Marine units will have these weapons; most other units will not.

Merc 2000 Notes: The M-4 has worked its way into a lot of NATO and US units, and a civilianized version is also available. Civilian versions often have a fixed stock, and sometimes are not equipped with a flash suppressor; they usually don’t have bayonet lugs, either.

Notes: This is the standard combat rifle of the US, as well as having been used or being used by over 50 other armies. The M-16 rivals the AK-series for widespread use. The M-16 is an effective and popular weapon, but is a bit sensitive to dirt. The M-16 was originally designed by the small arms genius Eugene Stoner, based on the AR-10’s action and a development of the .222 Remington round, which was designed to fall in range, penetration, and wounding potential somewhere between the 7.62mm NATO round and the .30 Carbine round. The US Army had expressed a desire (against the wishes of the DoD) as early as 1957 for a light rifle to replace the M-14 as its standard assault rifle, which had already proven to be too heavy for regular troop use and uncontrollable in automatic fire. The prototypes went through several iterations based upon troop and small-arms-expert evaluations. Different ammunition types also were tried, and the AR-15 (as the M-16 was called at the time by Stoner) also faced fierce opposition from the DoD’s Chief of Ordinance, who wanted to stick with the M-14. This meant that official adoption, first by the USAF, did not occur until 1962, who issued it to their security troops), and later that year, for use by SEAL and Special Forces advisors in Vietnam.

Since the SPIW program essentially produced nothing acceptable to the military, Secretary McNamara finally intervened and told the Army to accept the M-16, first for special ops, airborne, Air Cav, and air assault troops, and then later for the Army and Air Force in general. This crash program unfortunately led to quality control problems, which were only partially rectified.

The original M-16 contained most of the features which became standard on future M-16s. It uses the now-standard 20-inch length barrel, though the flash suppressor is slightly different than on later models (though still of the slotted type), and is also made of light alloy instead of the steel of later models. It has no forward assist, and the chamber and barrel are not chromed, which led to quick corrosion and fowling in Vietnam’s climate. (Air Force Security troops, for the most part not operating in such environments or in the bush, didn’t really have this problem.) At the time of issue, the M-16 was still using the IMR Ball propellant recommended by Eugene Stoner, which also greatly decreased fouling and corrosion.

The M-16A1 is perhaps the most common version of the M-16. The original M-16A1s quickly suffered from not being used with IMR Ball propellant (instead, the military decided to go with a much cheaper propellant that caused much more fouling and corrosion, and though they later changed to better-quality propellant, it still did not match the quality of the original IMR Ball propellant), a myth that sprang up among soldiers that the M-16A1 didn’t require any regular cleaning, and a barrel and chamber that corroded rapidly. Thus, the M-16A1 quickly gained a reputation of jamming, usually at the wrong moment. The problems with corrosion were largely fixed by chroming the chamber and barrel. The M-16A1 also introduced the forward assist, which is sort of plunger that can be used to fully close the bolt when the M-16A1 is fouled inside the receiver or otherwise does not seat properly. (This feature as added at the insistence of the Army and Marines; the USAF also has some M-16A1s, but most of them don’t have forward assists, and are often mistaken for original M-16s.) The T-bar charging handle was made wider, the slotted flash suppressor was changed to steel construction (and later changed to the now-familiar birdcage pattern), and the magazines were changed from steel to an aluminum alloy (including a new 30-round magazine introduced in 1969). Most of the problems experienced with the M-16A1 can be traced back to improper maintenance (personally, even though I have always cleaned my weapons thoroughly, have always had problems with extraction failures on both the M-16A1 and A2, however, as did many of my fellow soldiers). The recoil buffer had mass added, which both curbed the too-high cyclic rate and also corrected a problem where the bolt tended to literally "bounce" inside the receiver, resulting in a bolt which did not close properly. It should be noted that in addition to Colt, many M-16A1s were manufactured by GM’s Hydra-Matic division and Harrington & Richardson. (The M-16A1s built by these two alternate manufacturers actually turned out to be superior in quality to those manufactured by Colt!) The M-16A1 has turned up in some strange places; for example, leftist rebels in Nicaragua, El Salvador, and Guatemala were often encountered with it. The serial numbers on the captured M-16A1s were traced to weapons lost or abandoned in Vietnam before US involvement in that country ended. In addition, some 30+ countries are licensed to manufacture the M-16A1, so they may be encountered pretty much all over the globe.

Though the US Army was satisfied with the M-16A1, the Marines were not. In 1980, they began to tinker with the M-16A1, producing the M-16E1A1, which eventually resulted in the M-16A2, which was adopted by the Marines in 1983. Changes made for the M-16A2 included better chroming for the chamber and barrel, a change to a 1:7 rifling twist (from 1:12) to suit the superior SS-109 ammunition which had been developed by FN and Heckler & Koch, the omission of the bottom slot from the flash suppressor (allowing it to function as sort of a partial muzzle brake), and a small block added behind the ejection port to deflect hot brass away from left-handed shooters (hot brass often ends up in the shirts or face of left-handed shooters of the M-16 and M-16A1). The handguard was changed from its triangular cross-section to a round, ribbed criss section; this is not only ergonomically better, but simplifies the supply chain by eliminating the need to have left and right handguard sections. They also dissipate heat better. The pistol grip was also redesigned, with finger swells. The formerly solid polymer stock was replaced with a fiberglass/nylon composite which is filled nylon foam, which helps counteract the fact that the M-16A2 is heavier elsewhere, and is also far stronger than the original stock. The rear sight is replaced by one which allows adjustments for windage and elevation by simple dials (on the M-16A1, windage adjustments had to be made by sticking the point of a bullet or other object into holes in the adjustment dials, and elevation was done on the front post in the same manner). Perhaps the most controversial change was the fire selector; the capability for fully automatic fire was replaced with a 3-round burst feature, with a cyclic rate so high that the recoil from the first round is not felt until the third round is already out of the barrel. The barrel is the subject of more misunderstanding than anything else on the M-16A2; it is roughly double the thickness, but only at about the last third of the barrel. Many think this is to increase accuracy (untrue), to increase heat dissipation (mostly true), and to stiffen the barrel (a little bit true). However, the primary reason for this thickening is a reflection of grunt mentality; the primary reason this was done is to stop soldiers from bending the barrel when using their rifle as an ad hoc crowbar.

The US Army was originally quite reluctant to accept the M-16A2; they did not want to have to switch to SS-109 ammunition since they had mountains of old M-193, and they did not like the burst fire mechanism, as they felt that the ability to produce massive quantities of firepower increased the confidence and morale of its troops. (In essence, they were underestimating their people.) Ironically, a version of the M-16A2 was made with full-auto capabilities, but they were built only for export as the request of certain customers, and not used by the US military. However, in 1985, they were basically forced by the Pentagon to adopt the M-16A2. In addition to the full-auto M-16A2 mentioned above, other versions built for specific export customers include an M-16A2 with full auto features as well as M-16A1-type sights, and an M-16A2 with a medium-weight M-16A1-type barrel.

The M-16A3 is identical to the M-16A2 but has a removable carrying handle that is mounted on a MIL-STD-1913 (for better mounting of optics) and is without burst control. This version is the current standard version of the M-16A1 for the US Army and Marines, and is often seen with an ACOG-type sight mounted on the rail rather than standard iron sights. The M-16A3 also restores the full-automatic feature to the M-16, in lieu of the 3-round burst feature. The M-16A4 is identical to the M-16A2 except for the removable carrying handle and MIL-STD-1913 rail, and uses the selector with the 3-round burst feature.

Other variants of note include the AR-15 HB, also known as the Model 606 or Heavy Assault Rifle M-1. The "HB" stood for Heavy Barrel;" the AR-15 HB was a variant of the M-16A1 designed for use as a squad automatic weapon or as a weapon for what would now be called a designated marksman. The AR-15 HB could take a detachable version of the BAR’s bipod or a standard scissors bipod. The Model 606A was essentially simply a heavier-barreled M-16A1, and the Model 606B was the same weapon, but with an additional selector position to allow burst fire. Only a few hundred were built, primarily for field and combat evaluation use.

The AR-15, AR-15A1, AR-15A2, and AR-15A3 are civilian versions of the M-16/M-16A1/M-16A2/M-16A3; they cannot mount a bayonet, and usually have been "fixed" so that a conversion to automatic fire is beyond the abilities of normal gun owners or even armorers of normal skills. Those few versions built during the Assault Weapons Ban period (even variants built by other companies) usually have no flash suppressor, and were sold with 5 or 10-round magazines (though they can still accept any sort of M-16-type magazine).

Though many special variants of the AR-15 have been made (most by private gunsmiths), some of them include the AR-15 HBAR (Model 611), which is a civilian variant of the AR-15 HB above; it has no bayonet lug nor a forward assist. The Model 611P is a Model 611 built in the Philippines, and the Model 621, which was built for export but is otherwise identical to the standard AR-15 HBAR. The AR-15A2 HBAR (Model 737) is based on the AR-15A2, with the heavier barrel (essentially, the barrel is heavy throughout its length, instead of just the last third); however, it uses M-16A1-type sights. The AR-15A2 Delta HBAR (Model 741) replaces the carrying handle and rear sight with a special mount for a Colt-designed rubber-armored 3-9x sight, and an ambidextrous raised cheekpiece (with an undercut for pulling back the charging handle). The Delta HBAR was introduced in 1987, but was produced for little over a year. The AR-15A3 HBAR (Model 941) is basically the same as the AR-15A2 HBAR, but has a MIL-STD-1913 rail instead of a carrying handle.

Like the M-4, there have been many accessories designed for the M-16 series, ranging from new handgrips to different flash suppressors or even firing different ammunition. The first underbarrel grenade launcher, the M-203, was designed specifically for the M-16A1.

Meanwhile, in Iraq and Afghanistan, the Army and Marines have been using specialist versions of the M-16A3; the Army calls theirs the SDM-R (Squad Designated Marksman Rifle), while the Marines call it the SAM-R (Squad Advanced Marksman Rifle). These are "semi-sniper rifles," designed for sharpshooters assigned to squads of troops who are not trained as full snipers. The SDM-R itself comes in two models – most are in fact based on the M-16A3, but the 82^nd Airborne and 101^st Air Assault Divisions employ many that are based on a flattop version of the M-4 Carbine. (It should be noted that DPMS Panther also makes a civilian model of the SDM-R, which is virtually identical.) The SDM-R and SAM-R use a heavy, match-quality barrel, and the carrying handle is replaced by a MIL-STD-1913 rail which extends from the receiver to the front sight post. No rear iron sights are normally used, but can be added to the rail. The front sight can also be removed as required. The barrel is 20 inches long and is free-floating, but uses a 1:8 twist to accommodate both standard SS-109 ammunition and match-quality rounds, and is made from stainless steel. The trigger and fire mechanism has been replaced by a two-stage match trigger, and the SDM-R and SAM-R are semiautomatic-only weapons. On the handguards is mounted a Harris S-L light bipod, adjustable for height and cant. The M-4-based version is identical except for the 14.5-inch barrel. The cost of these weapons below include a compact telescopic sight.

Twilight 2000 Notes: The M-16A3 and A4 do not exist in as great a quantity in the Twilight 2000 timeline as in the real world; nor does the AR-15A3 and its HBAR variant. The SDM-R and SAM-R were in fact made in the Twilight 2000 timeline, both in the US and by local armorers; however, in the Twilight 2000 timeline, they are called the M-16A3E1 and M4E1.

Notes: Development of the AR-15/M-16 into a carbine variant (with a mid-length barrel, unlike the CAR-15 and its ilk) began in the late 1960s; ironically, the first carbine variant was designed for civilian and police use instead of military use. The Model 605A had a 16-inch barrel and was based on the M-16A1, complete with forward assist. Civilian versions had a solid stock and were rigged to fire on semiautomatic; police could get a version with a four-position folding stock and with full-auto capability. The police version also had the unusual feature (at the time) of having an additional selector lever position allowing for two-round bursts. The handguard was shortened appropriately, but still used a triangular cross-section with left and right handguard halves. A Model 605B version was also designed; this version had a 15-inch barrel, full-length handguards with just the muzzle and front sight stand protruding (which probably looked rather strange), the four-position selector, and the collapsible stock. Neither of these variants could use a bayonet or an underbarrel grenade launcher, and they used the prong-type flash suppressor. They also did not sell very well, though some small amounts were sold to civilians and police departments.

The Model 651 was designed shortly thereafter; it was based on the M-16A1, and had a solid stock and a 14.5-inch barrel tipped with a prong-type flash suppressor. The Model 651 was designed primarily for export but I have not been able to find out how many sales were made. The Model 652 is basically identical, but has no forward assist. The Model 653 and 654 are identical to the Models 651 and 652 respectively, except for their collapsible stock. The Model 653 was also license-built in the Philippines; these were known as the Model 653P.

The M-4 is a cut down carbine version of the M-16A2. This weapon, unlike most of the M-16-based carbines and short assault rifles, can mount the M-203. The weapon was designed for paratroopers and special ops troops, to allow them to jump with their weapon uncased (for faster access during combat jumps), as well as to replace the M-9 pistol in some roles, but is becoming the standard assault rifle in many other types of US units as well. The British SAS and SBS also use a large amount of M-4s, particularly the M-4 SOPMOD.

Operation of the M-4 is essentially the same as that of the M-16A2 (in fact, they share a receiver and its internal components), but the barrel is 14.57 inches long (officially, 14.5 inches long). The barrel is tipped with the same flash suppressor as the M-16A2, and fires on semiautomatic or three-round bursts. The stock is a four-position sliding one, with a lever on the underside of the buttstock allowing for this sliding. The M-4A1 is essentially the same weapon, but has the burst-fire mechanism replaced by a full auto setting. There is also a version of the M-4 (alternatively called the M-4A1E1, M-16A3 carbine, Colt Model 923, and M-4A2), which is an M-4, complete with the burst mechanism, but the carrying handle replaced with a MIL-STD-1913 rail. Another version of this carbine as the burst mechanism replaced with a full-auto setting, but I don’t know what official designations have been given to this version. In the charts below, I call them the M-4A1E1 and M-4A1E2.

With US special ops units using the M-4A1 variant so much, the US Navy Special Warfare Center developed the SOPMOD kit for the M-4A1 (which will also fit any of the M-4 series). The M-4 SOPMOD replaces the carrying handle with a MIL-STD-1913 rail, and a RIS (Rail Interface System) replaces the standard handguards, providing four more MIL-STD-1913 rails where the standard handguard was. This allows the M-4 SOPMOD to mount a dizzying array of accessories and optics, as well as items such as an underbarrel grenade launcher or shotgun kit. The types of accessories are limited only by the imagination of the shooter and what the mission calls for. (The player who is equipped with an M-4 SOPMOD may choose up to $300 of accessories for his rifle, and these are included in the cost.)

The Model 723 is based on the M-4; it shares the M-4’s general features, but has M-16A1-type sights and a slightly-longer 14.57-inch barrel. The Model 723 is also built to the same standards as an M-4 SOPMOD model. As with the M-4 SOPMOD, the player may choose $300 worth of accessories for his Model 723 as part of the cost of the weapon. Though primarily exported to the United Arab Emirates, it also used in small numbers by US Special Forces (reportedly actually Delta Force) under unknown circumstances.

Twilight 2000 Notes: Airborne, special ops, and some Marine units will have the M-4 series; most other units will not.

Merc 2000 Notes: The M-4 has worked its way into a lot of NATO and US units, and a civilianized version is also available. Civilian versions often have a fixed stock, and sometimes are not equipped with a flash suppressor; they usually don’t have bayonet lugs, either.

Notes: There have probably been innumerable short and micro versions of the M-16 built over the past 40 years, both for the US and for (and in) other countries. Most of them are simply shortened M-16s of various types built using different manufacturing methods, different stock lengths or pistol grips, or slightly different materials, but most of these conform to the other examples shown here.

The CAR-15/XM-177 series is one of the more ubiquitous members of this sort of weapon. The first CAR-15 appeared in 1965 for use by US Army Special Forces in Vietnam, to give them a lighter carry weapon and one that was more suited to Vietnam’s short-ranged combat. The original CAR-15 was simply an M-16 with the barrel chopped in half to 10 inches. The prototypes had shorter versions of the M-16A1’s triangular handguards, but the ones that reached combat had round, ribbed handguards. The stock remained solid, but was shortened a little. Unfortunately, the flash suppressor remained the original prong-type, and that was its greatest problem -- the abbreviated barrel spat out a large amount of unburned powder, muzzle blast, and muzzle flash in general. In a firefight, the shooter became effectively deafened in a matter of seconds, and at night, blinded as well.

The US Air Force envisioned a version of the CAR-15 which could be carried disassembled in a pilot’s survival pack (mostly by the pilots of heavy aircraft and helicopter crews). This had several variations from the CAR-15; the stock was a tubular fixed detachable stock 3 inches shorter than a standard M-16 stock, the pistol grip was shortened, and the muzzle sported a cone-shaped flash hider. They were to have been issued with 10 or 20-round magazines. It was quickly judged that the CAR-15 Survival Rifle, as the weapon was known, was still too large a package to be carried in a pilot’s bug-out pack.

The CAR-15 Survival Rifle was a non-starter, but Special Forces realized CAR-15 itself showed some promise, with a major overhaul. First, the prong-type flash suppressor was discarded in favor of a much larger flash/suppressor/muzzle brake that did a much better job of suppressing the muzzle blast and flash. Second, the stock of the CAR-15 Survival Rifle was greatly improved, turned into a four-position sliding stock, and fitted to the new weapon. Third, the pistol grip was restored to the standard length of an M-16’s pistol grip. This resulted in the XM-177, also known as the CAR-15 Commando (the weapon was never released from its experimental designation, and was always a limited-issue weapon), and the GAU-5/A/A (the US Air Force’s designation; at that time, three different designation systems were used, depending upon the branch of service using the weapon) which appeared in 1965. Like the Air Force’s M-16s, the XM-177 had no forward assist. The GAU-5/A/A version that was first issued to the Air Force had a very stubby 9.8-inch barrel; problems with the GAU-5/A/A (primarily due to The XM-177’s Stoner-designed gas system for the M-16 series not really being designed for a barrel of 10 inches or less without considerable modification) led quickly to the GAU-5/A/B, with a slightly longer 10-inch barrel. The XM-177 was meant for issue to Air Force Security Police, but was primarily issued to the newly-forming elite Pararescue teams that were subsets of the PJs.

Shortly thereafter, the XM-177E1 version appeared; this version was essentially the same as the GAU-5/A/B version of the XM-177, but based upon an M-16A1 receiver with its forward assist; there was also a slight weight difference. Though intended for special operations use, carrying an XM-177E1 became a sort of status symbol among line officers and senior NCOs. In 1967, the barrel was lengthened to 11.5 inches, to reduce the amount of unburned powder and to increase the reliability of the weapon. This version was known as the XM-177E2, which became the most common of the XM-177/CAR-15 series. The XM-177E2 was also capable of mounting the then-new M-203 underbarrel grenade launcher. Collectively, the XM-177 series was known as the Commando series. (Trivia note: Most of the time when people see pictures of troops in Vietnam or slightly later and think they are seeing a CAR-15, they are actually seeing an XM-177E2.) The XM-177E2 was primarily issued to special ops units, LRRPs, and such troops, and was rare in line units. The USAF also used a further modified version of the XM-177E2, which they called the GAU-5P; this version had the barrel lengthened to 14.49 inches (making it more a carbine than a short assault rifle, but included here for completeness).

Functioning members of the XM-177 series are today difficult to find; US special ops units continued to use them well into the 1980s, and many other XM-177s were cannibalized to provide spare parts for other XM-177s (Colt stopped producing XM-177 parts in the 1970s), and most XM-177s had been shot out by the time they were replaced.

Some time after the advent of the M-16A2, special ops again expressed a desire for a Commando variant of the M-16A2. Though (as far as I can tell; I’m not quite sure on this, and I invite corrections), it was designated the M-6 Carbine, it appears to be called simply the Commando or M-16A2 Commando most of the time. It is based on the M-4 Carbine, but has a shortened 11.5-inch barrel tipped with a standard M-16A2/M-4 flash suppressor. The 3-round burst mechanism was replaced with a full-auto sear, but there is also an M-6A1 version with a 3-round burst feature instead of the full-auto feature. Though more modern propellants and cartridges lessen the muzzle flash and blast, this is reportedly a problem with these versions of the Commando. Lately, pictures from Iraq and Afghanistan have been seen showing troops armed with flat-topped Commandos with MIL-STD-1913 rails atop the receiver, but I don’t know the designation of this version. (I have called it the M-6A2 below.)

This brings us to a rather weird variant of the M-16 series: the M-231 Port Firing Weapon. (No, that’s not backwards; that’s the proper designation of the weapon.) This version was specifically designed for used from the firing ports of the Bradley series of Infantry Fighting Vehicles. In its early phases, the M-231 program came down to the Colt version or a version of the Heckler & Koch HK-53, but in the interests of interoperability, the Colt version won out, and became the M-231 PFW. The M-231 has a 14.49-inch heavy barrel (primarily to minimize overheating) tipped with a standard M-16A2 flash suppressor. Just ahead of the short handguard are wide threads which allow the M-231 to be quickly screwed into the Bradley’s firing point swivel ball. Sighting was meant to be done through primarily through the vision block above the firing ports, with the magazines of the M-231 filled with tracers to allow the shooter to adjust his fire quickly. Feed is from standard M-16 magazines, and internally, the M-231 is for the most part the same as the M-16A2. However, the M-231 fires from an open bolt and the cyclic rate was greatly increased up to 1100-1200 rpm, to provide better suppressive fire. The right side of the M-231 has integral attachment points for a canvas brass catcher. The design of this bag also allowed the fumes from firing the M-231 to be vented outside of the Bradley. Though the infantrymen inside the Bradley also have M-16A2s or M-4s to grab when they exit the vehicle, the M-231’s could be quickly dismounted and used as conventional short assault rifles if necessary. The M-231 has no iron sights; the trough of the carrying handle is to be used as an emergency short-range sight when the M-231 is dismounted. Early versions of the M-231 were issued with a sliding wire stock for use if dismounted, and even a stock which clipped onto the buffer tube was experimentally tried. The wire stock (or a stock of any kind) was later discarded as being unnecessary, especially after the side firing ports of the Bradleys were plated over in the interests of adding more side armor.

Twilight 2000 Notes: The XM-177E1 and E2 were rarely seen in military service by the time of the Twilight War, but they were later pulled out of storage and put to good use, mostly by Milgov and Civgov forces inside the US, despite their generally poor condition. The M-231 had even wider use than was intended by the designers; they were often stripped from immobilized Bradleys and used as assault rifles by both military and civilian forces, often with the addition of stocks removed from non-functional M-16s, M-177s, CAR-15s, or M-4s; M-231s were also seen with homemade wooden stocks or sliding wire stocks.

Notes: The idea behind this weapon was to produce a compact version of the M-16 while avoiding the massive muzzle blast and firing signature that such a weapon normally produces. To this end, Arms Tech used a standard M-16 lower receiver and paired it with a modified upper receiver using a specially designed barrel shroud/muzzle brake. The standard buttstock was replaced with a sliding wire stock, and the carrying handle was replaced with a Picatinny Rail (the stock Compak-16 comes with an Occluded Eye Sight licensed-produced from a South African design).

Twilight 2000 Notes: Though it had little success with the military or police, survivalists and militia members in the US liked the weapon, especially female members.

Merc 2000 Notes: This is mostly a civilian niche weapon, though there has been some experimentation by the US military, the CIA, and various Federal agencies.

Notes: Expanding on the US Navy SEALs’ special version of the M-4 Carbine generally known as simply the SEAL Recon Rifle, the Mk 12 SPR (originally meaning Special Purpose Receiver, but now said by the Pentagon as standing for Special Purpose Rifle) is a very highly-modified version of the M-16/M-4 series, blending features of the M-16A4 and M-4A1 as well as having a plethora of new and different features that essentially make the Mk 12 a distinct subtype of the M-16 series (or perhaps even an altogether different rifle).

The Mk 12 was designed from the outset to use the Mk 262 version of the 5.56mm NATO cartridge; this round uses a heavier 77-grain bullet (the standard 5.56mm NATO bullet is a 62-grain bullet), along with a slightly higher powder charge and a different propellant mix. (Unfortunately, there is no really adequate way to simulate this in the Twilight 2000 v2.2 rules; I’m essentially fudging as best as I can in the fire chart below.) The Mk 12 can fire other types of 5.56mm NATO rounds, but generally with relatively poor results. Many of the details of the Mk 12 are still classified, but it appears that most of the upper receivers were given the "Canadian treatment" – manufactured in Canada by Diemaco instead of by Colt or Armalite. Most Mk 12’s don’t carry much in the way of markings, if any, so it can be difficult to tell. The upper receiver is still made from aluminum alloy, but it appears that it is made of stronger stuff than that of the standard M-16 series. Like the M-16A4, there is no carrying handle; the receiver is instead topped by a MIL-STD-1913 rail. In photographs from Afghanistan and Iraq, some of these rails top only the upper receiver, while some extend from the upper receiver all the way down the handguard.

The lower receiver is also of strengthened aluminum alloy; it appears to house an improved version of the standard M-16-type gas operating system, using a bolt with an improved extractor and case ejector. Oddly enough, the trigger system, while built by KAC, is derived from that of the M-16A1, modified to use a two-stage trigger mechanism.

The barrel itself is 18 inches long, match quality, free-floating, heavier than the standard M-16A4 barrel, and threaded at the end to allow the easy attachment and detachment of a variety of muzzle devices. They also have a collar to allow the attachment of muzzle devices which do not use threads. Though they appear in photographs with a variety of muzzle devices, the most common appears to be a muzzle brake similar to those designed by OPS, Inc. The barrels themselves are known to be manufactured by Douglas Barrels especially for the Mk 12, from stronger yet lighter steel, and have a 1:7 rifling twist.

The buttstocks of the Mk 12 SPRs seem to be the most variable feature of these rifles; they have been seen with M-16A1 stocks, M-16A2 stocks, M-4 sliding stocks, and special sliding stocks designed by Crane NWSC which have several compartments for small accessories and are more adjustable than the M-4’s stock. In addition, every so often some other type of stock is seen; it appears that the SEALs, Special Forces, and Rangers are still experimenting to find the optimum stock.

Handguards are longer, wider, and of a different profile than M-16-type handguards; they are also made from carbon fiber and do not touch the barrel at any point. Another common handguard seen on the Mk 12 is a specially-made version of the KAC M-4 Free-Floating RAS handguard, with 4-point MIL-STD-1913 rails (and still do not touch the barrel at any point). Flip-up iron sights are provided at the rear; they are dial-adjusted and allow for finer elevation and windage adjustments than standard M-16A2/A3/A4 rear sights. The triangular front sight post is deleted, replaced by a flip-up front sight assembly. Again, several types of iron sights have been observed. In addition, the Mk 12 is commonly seen with a wide variety of optics attached to the MIL-STD-1913 rails. In most cases, these optics are attached with quick-release mounts that allow the optics to be changed and/or removed and reattached without losing the weapon’s zero.

Early Mk 12’s were seen with Versa-Pod folding bipods, which do allow for limited cant and height adjustments, but were found to be not adjustable enough and to not have the robustness required for their role. The Versa-Pods were therefore replaced with Harris-made folding bipods, which are stronger and more finely-adjustable.

There are two known versions of the Mk 12 listed as being in use: the Mk 12 Mod 0, used by US Army Special Forces and Rangers, and the Mk 12 Mod 1, used by US Navy SEALs. What the differences are between the two are unclear at this point.

I will freely admit that, until I have more information, the statistics below are essentially educated guesses, and could be partially or even entirely wrong. I will update as more information becomes available (if ever).

Twilight 2000 Notes: The Mk 12, as such, is unavailable in the Twilight 2000 timeline; however, it is a fair bet that such weapons would appear as experiments at the very least in the Twilight 2000 timeline.