|This article, MA6 assault rifle, was written by Athena32. Please do not edit this fiction without the writer's permission.|
- "Makes you feel like Death himself, shredding bad guys with the MA6 and watching their bodies fall riddled with holes. It's always been like that though. They've been used by the UNSC for so long now, they're practically in the blood."
- ―Anonymous UNSC Marine
The MA6 assault rifle officially called the MA6A Individual Combat Weapon System, was a bullpup, air-cooled, gas-operated, selective fire infantry rifle in use with the UNSC during the Remnant War and the first years of the Galactic War. Designed to replace the venerable and extensive , the MA6 became the service rifle of all three branches of the UNSC after replacing its predecessors. Accurate, sturdy and relatively lightweight, the MA6 was essentially the same weapon as the MA5A and its successor, the MA5C, though featuring modernised materials, design and ammunition. Universally popular, the MA6 was the most commonly issued weapon within the UNSC during its service, alongside the more specialised M62 battle rifle. The MA6 was chambered for the 7.62x51mm NATO full power rifle cartridge, which gave it significant stopping power and range whilst being suitable for controlled, accurate automatic fire.
The MA6 drew heavily on not its direct predecessor, the MA5C, but its ancestor, the MA5A for design influence. The MA5A had been the most successful of the MA5 series and had served as the UNSC's service rifle since the 2430s. The rifle was accurate, sturdy and popular, and benefited from a number of design elements that maximised both accuracy and power. The MA5A was the most commonly issued infantry rifle and was extensively supported by modification and adaptability methods, which allowed it to remain competent despite combating a technologically superior enemy. The MA5A utilised the 7.62x51mm NATO ammunition; although this suffered from low stopping power compared to other infantry rifles, notably the round utilised in the , its small size allowed for sustained rate of fire and low recoil, making it ideal for use in an assault rifle.
The MA5A was replaced by the equally effective MA5C, a relatively popular rifle that quickly gained a good reputation, and was considered comparable in most aspects to the rifle series it replaced. The MA5C was used by the UNSC from the end of the Great War until the turn of the century, with various models and upgrades throughout its service life. The UNSC sought a replacement for the ageing family after the Human-Covenant War in the early 2550s, with the MA6 drawing on the well-liked and effective MA5, effectively taking the basic design and fully modernising and heavily updating it.
The MA6, like the MA5C that preceded it, was the UNSC's service rifle, or standard infantry rifle, used in larger numbers than any other infantry rifle. It was lightweight, accurate, powerful and above all, reliable, guaranteeing its successful use in any action the UNSC was involved in. The MA6 was introduced in the late 2550s and served as the staple UNSC rifle during the Remnant War, which concluded in 2565. The rifle continued to serve until the 2620s, seeing action in the Galactic War, until it was replaced by the M28 assault rifle as part of a wider UNSC modernisation program.
The MA6 was used as the 'bread and butter' of UNSC infantry weapons; as the UNSC's service rifle, it was issued in numbers far greater than other small arms, with the only other weapon issued in comparable numbers being the M62 battle rifle. The MA6 was widely used by Marines, both in shipboard and land-based combat, and by UNSC Army troops. At close range the MA6's high rate of fire made it a powerful weapon which could defeat most enemies, and at mid ranges automatic fire was accurate enough to be effective. At longer ranges burst fire and semi-automatic modes sacrificed rate of fire for accuracy, which decreased lethality somewhat but maintained accuracy, making it useful even at longer ranges. The MA6 was at home in almost any environment, being widely used in conditions such as tight urban areas and building interiors, and wide open expanses of grassland or desert.
The most striking aspect of the MA6's design was its bullpup layout, which positioned the action and the magazine behind the trigger. This layout increased barrel length compared to the overall weapon length, which had the effect of increasing muzzle velocity and therefore range. The MA6 saw numerous drastic changes from the MA5C, most notable being the removal of the integral computer system along the weapon's upper receiver. The forward handgrip was also dramatically changed, slimmed down so that it was thinner than the barrel section above it and possessing mounts for a rail interface system. The majority of the weapon's upper receiver was taken up by an attachment rail, which commonly mounted aiming optics; iron and reflex sights were common although telescopic sights were also effectively used. The weapon's upper receiver mounted a fore and rear foldable, removable ironsights that featured as standard on the weapon; they were frequently removed upon the use of more advanced optics. Behind this rail, above the action and firing mechanism, was a cheek rest that assisted with accurate firing, although this could be removed at the user's discretion. The weapon's handguard, sides, stock and the ergonomically-designed pistol grip were constructed from lightweight FRP (fibre-reinforced polymer) made of a polymer matrix reinforced with fibres (a carbon fibre/kevlar mix), which was lightweight yet strong and resistant polymer. The upper receiver, rails and magazine assembly were constructed from high grade steel, while the barrel and firing mechanism were precision-machined titanium alloy. The rifle was modular, meaning that it was assembled in interchangeable sections that were easy to separate and replace, in addition to its rails which accepted a wide range of attachments.
The MA6 was a relatively light weapon, especially when compared to its predecessors, which meant that recoil control was imperative, more so considering its selective fire ability. Several hydraulic buffers linked to the weapon's microprocessor accurately controlled recoil, effectively attempting to cancel it out it and reducing it considerably. The weapon also featured a venting system that recovered part of the gases generated by the round, and pushed it back in a space located behind the bolt during the cycle. This caused the bolt to 'bounce' on a sort of 'gas cushion' that acted as a buffer, dramatically reducing the weapon's recoil. It also featured energy absorption mechanisms in the buttstock, absorbing energy and reducing felt recoil. The weapon's bullpup nature meant that it was somewhat back-heavy; however, the recoil reduction mechanisms largely balanced this out, and its rather heavy barrel and forward grip combated any muzzle climb. The barrel end featured a large, birdcage-type flash suppressor which reduced the barrel's muzzle flash and directed it away from the shooter's vision; as a secondary function this vented excess gas in a way counteractive to the weapon's muzzle climb and backwards recoil.
The MA6's forward handgrip served as a mounting point for an additional three rails; one on each side and a third along the bottom edge. The weapon maintained its integral flashlight from previous generations, though this was much more compact to fit into the far smaller handgrip section. The MA6's cocking handle was located above the fire mode selector, and was accessible through both sides of the weapon. The bolt remained stationary locked back while the weapon was in operation, and slid forward when the magazine was empty. The handle then needed to be slid back again when a new magazine was inserted, to chamber the first round and move the striker to the ready position. Behind the ergonomically designed grip and trigger assembly was the magazine well, which was linked to the grip to form a crude thumbhole stock. The weapon accepted as standard the M9 Magazine, which held 42 caseless rounds in two staggered columns. The magazine release was located just above the magazine port on both sides of the weapon. The weapon's stock was adjustable, and had a maximum extension of 9 centimetres. As the MA6 utilised caseless ammunition, it lacked an ejection port or any mechanism of extracting and ejecting a casing.
The MA6 used 7.62x51mm NATO ammunition, which was a commonly used round in assault rifles and light machine guns. Lighter than most UNSC calibres, it was nonetheless perfectly suited to selective fire infantry rifles such as the MA6; the round offered controllable recoil together with good range, accuracy and adequate stopping power. The round achieved less range and power than other infantry cartridges, notably the 9.5x60mm battle rifle round, due to its smaller size and decreased kinetic energy; however, this allowed for higher rates of fire and more controllable weapons, balancing its capabilities out and affording it good suitability for assault rifle type weapons.
The weapon, like nearly all UNSC weapons, utilised caseless ammunition, which had several advantages over traditional cased ammunition. This was a major change from Great War-era weapons, which utilised rounds which contained propellant inside metal casings. From the conclusion of the Human-Covenant War onwards, the UNSC worked on increasing the lethality of its infantry firearms; aside from the development of directed energy weapons, one element the UNSC looked at was the application of caseless ammunition. This was already used with operational success in the M7/Caseless Submachine Gun, though was limited to this weapon and not available in other calibres. Developments in technology, however, allowed the widespread adoption of caseless ammunition from around two decades after the war onwards, with newer replacement weapons discarding more traditional ammunition.
Unlike experimental caseless munitions of the late 20th century, the MA6's ammunition maintained a tolerance similar to traditional, cased bullets. This was achieved by the propellant being coated in a thin layer of water, heat and dirt resistant coating. This also allowed rounds to be handled and manually loaded, as well as improving their 'drop resistance' or shock tolerance significantly. This also increased its shelf life considerably. These qualities were present in the M7/C Submachine Gun's ammunition, and carried over to the UNSC's next generation of caseless weapons.
Caseless ammunition offered several advantages. The most noticeable was an increase in muzzle velocity; not only was more propellant available per bullet with the caseless system, the propellant released significantly more energy when combusted. This higher muzzle velocity led the MA6 to deal noticeably increased damage to the target in terms of kinetic effects; this also markedly improved its armour and shield penetration characteristics. The 7.62mm round's muzzle velocity was typically two to three times higher with caseless ammunition than traditional cased types, making it significantly more effective than its more traditional predecessors and meaning even assault rifles were capable of taking on shielded and armoured Covenant infantry. It was largely this increase in lethality that convinced the UNSC to maintain ballistic weapons for the bulk of their weapons, rather than developing and adopting plasma weapons of their own.
Caseless ammunition also reduced the complexity of the MA6's internal mechanisms, as there was no need for extraction and ejection of spent casings. As the overall round was smaller, it allowed for larger capacity magazines, and its significantly reduced weight increased the amount of ammunition a soldier could realistically carry.
The 7.62mm bullet was actually embedded inside the solid propellant 'block'; it, the bullet and the primer were held together by a combustible glue. When fired, everything in the chamber save the bullet fully combusted, leaving no residue in the chamber and propelling the bullet down the barrel. The propellant itself was an advanced solid, plasma-based substance similar in composition to that of the the experimental M634 HP-SAP, which gave high muzzle velocity; this in turn increased lethality on contact with the target. The block was highly resistant to temperature, which prevented it from combusting prematurely, for example on contact with heat inside the weapon, or external heat sources.
There were numerous forms of 7.62x51mm NATO ammunition available to the UNSC, each differing in usage and effects. This varied from the simple and cheap to the complex and expensive to manufacture. The most commonly issued and utilised round was the M602 S/AP-HE, or Shield/Armour Piercing-High Explosive, which was a balance of potency and cost. Specialised ammunition, such as the M601 SAP-HEI, was generally only issued to high priority units and special forces, while forms such as the M603 Jacketed Hollow Point specialised to a degree where they were limited in their effectiveness, and as a result were not commonly issued.
- M601 Semi-Armour Piercing-High Explosive Incendiary: The M601 Semi-Armour Piercing-High Explosive Incendiary, or SAP-HEI, was an ammunition type combining both an armour piercing and an explosive/incendiary capability. The bullet's tip was filled with a highly incendiary chemical, which burned at several thousand degrees upon impact with a target, damaging or melting armour and heavily affecting shields. Behind this was a high explosive component which detonated immediately on impact with a target, further damaging the area. Behind this was a solid core penetrator of depleted uranium, held in a backing 'cup' of steel. The components were held together in a copper or lead jacket. Upon hitting a target, the incendiary and explosive properties would damage the target area, aiding considerably in the depleted uranium's penetration into the interior. The penetrator featured a self-sharpening tip and was itself pyrophoric, meaning that it ignited upon impact with the incendiary material. It then punched through any remaining armour, having been ignited at this point and also carrying with it any remaining incendiary material from the tip. Effects on the target, especially if it was organically-based, were catastrophically damaging; the round would typically bypass any present armour (following rapid depletion of shields) and propel an incendiary penetrator and secondary incendiary material into the target's innards. However, the round's complexity in design made it expensive and its use was usually reserved for special forces and select few line units.
- M602 Shield/Armour Piercing-High Explosive: The M602 Shield/Armour Piercing-High Explosive, also known as S/AP-HE, was the most common and effective type of ammunition employed in the 7.62x51mm calibre. The bullet itself was coated in a polymer which acquired an electric charge while in flight, aiding the bullet's kinetic energy in depleting shielding and, although it had little effect on armour, increased the bullet's drain on shielding by roughly half. The further the bullet travelled in the air, the greater the charge it acquired, so this effect was at its most potent at longer ranges and nearly negligible at extreme close range. The tip of the round consisted of a deforming ballistic cap; a lightweight element which crumpled upon impact with a target and gave the bullet superior aerodynamic characteristics. The bullet's armour-piercing core was a 'CVT' (Chromium Vanadium Tungsten) and Austenitic Steel alloy with a self-sharpening tip; when it fractured upon impact, it would do so in a way that the remaining element was still a sharp point. Behind this was a pre-fragmented block of 'TC3' alloy, composed of tungsten, cerium and copper carbide, with a delayed action fuze in the centre. This alloy maintained similar incendiary and pyrophoric properties to uranium, though without associated radiological effects. A millisecond after the bullet's penetration of the target, the fuze would activate; this fuze contained a plasma-based high explosive compound, which explosively fragmented the pre-weakened TC3, in turn heavily damaging organic structures and internal organs. As a secondary function the TC3 was incendiary, causing severe secondary damage to soft targets.
- M603 Jacketed Hollow Point: M603 Jacketed Hollow Point (JHP) round was a specialised munition for unarmoured and lightly armoured infantry, being at its most effective when utilised against Kig-Yar and Unggoy.
- M604 Tracer: The M604 Tracer
- M605 Armour Piercing High Explosive: The M605 Armour Piercing High Explosive round (AP-HE) was an effective armour defeating round, used as a cheaper alternative to more expensive semi-armour piercing high explosive incendiary (SAPHEI) ammunition. The bullet's tip was composed of a hollow, lightweight ballistic cap which deformed on impact, and improved the bullet's ballistic properties. Behind this was an armour piercing penetrator composed of CVT (Chromium Vanadium Tungsten) and Austenitic steel alloy, with a self sharpening tip. The remaining length of the bullet was comprised of 'stressed' steel; the interior of this steel was hollowed out and contained explosive filler and a delayed action fuze. Shortly after impact this would detonate, fragmenting the steel and causing effects similar to a miniature fragmentation grenade, albeit designed to detonate inside an organic body.
- M606 High Explosive Squash Head: The M606 High Explosive Squash Head round, or HESH, was designed to deal damage to a target without needing to defeat its armour, thus making it ideal for shielded and armoured targets. The bullet was formed of a thin steel shell filled with plastic explosive, with a delayed action base fuze towards the rear. Upon impact with a target the bullet would deform and form a disc or 'pat' of explosive with an increased surface area. A millisecond later the base fuze detonated, creating a shock wave that, owing to its large surface area and direct contact with the target, was transmitted through the material. The round was able to effectively defeat active shields due to primary kinetic, secondary explosive and tertiary kinetic effects. If impacting on armour, the round would cause little damage to the armour itself but directly damage the target through the resulting shockwave. This shockwave was highly disruptive to internal organs, often tearing vital organs from their connective vessels or reducing them to a thick paste. In some cases, the shockwave would cause a secondary effect known as spalling, where minute fragments of the armour's internal layer would be projected off it at high velocity, known as spall. In these cases secondary damage was enhanced by a sort of fragmentation effect inside the target's own body, and caused by their own armour. The round was relatively cheap to produce and was effective against unarmoured, armoured, unshielded or shielded infantry targets.