Weapon Name- 6.2mm 21-50B
Round Type- 6.2mm Caseless
Over-all length- 25.5 inches
Barrel length- 20 inches
Weight- 6.8 lb
Rate of Fire- 600 RPM
Feed Mechanism- Detachable top-fed magazine
Round Capacity- 60
Effective Range- 600 meters
Range- 1200 meters
Accuracy- 1 MOA
Accessories- Picatinny rails
Quick switch firing mechanism-
Scope/Sights- Picatinny rails
Muzzle Velocity- 850 m/s, 7.15 grams - 2600 joules
Firing System- G11 Rotating Chamber
Miscellaneous/electronic information- The weapon's firing mechanism is based on a shorted and simplified g11 rotating chamber system, which fires 6.2mm caseless rounds.
Basic Information
The weapon's firing mechanism is based on a shorted and simplified G11 rotating chamber system, which fires 6.2mm caseless rounds. The G11 system is essentially gutted, removing the hyper burst feature and instead modulated to a standard rate of fire of 600 RPM, designed to reduce the complexity and size of the G11. This reduces the weight and length, shortening the weapon, which is made bullpup, and makes it considerably cheaper and more reliable. The magazine does not reciprocate, and instead is fixed in place, which reduces recoil and decreases the mechanical complexity. What's left is the core principle of the weapon's functioning mechanism, a long stroke gas piston that reciprocates and spins a rotating chamber to allow rounds to be loaded in. This is more reliable and cheaper to mass produce, and have less recoil, which makes it easier to use. The weapon is based in part around the use of caseless rounds, using a high BC 6mm round. The round itself is 7.15 grams, plus 2.2 grams of propellant and an additional .4 grams of binder, weighing approximately 9.75 grams. This is lighter than a standard 5.56mm x 45mm NATO at 12.5 grams, or a 7.62mm NATO at 25.5 grams. Despite being larger and more powerful than a 5.56mm, roughly the same amount of ammunition can be carried in terms of weight, and roughly twice as much can be carried as the 7.62mm NATO. The very aerodynamic and long, high BC 110 grain (7.15 gram) cartridge is a large part of the weapon's design, having a G1 ballistic coefficient or .617, which gives it incredible aerodynamics and thus the ability to reach out to the same ranges as the much larger 7.62mm NATO round, despite being smaller, fulfilling a niche role that places in between these rounds in terms of performance. The round is also slightly more aerodynamic than the 6.5mm Grendel with a slightly flatter trajectory, but more or less possesses similar performance.
The round has very good long range performance, possessing more energy at 300 yards (1800 joules) than the 5.56mm at the muzzle, 1300 joules at 600 yards, more energy than a .357 magnum at 800 yards (1000 joules), and roughly the same energy as a standard handgun round while also still being supersonic to 1500 yards (400 joules). The 6mm has more energy than a 7.62mm NATO at 500-600 yards and beyond, meaning it actually performs better at these ranges despite the low initial muzzle energy. This incredible long range performance out does even the .308, and is vastly superior to the 5.56mm, which drops off in power substantially at 300 yards. The round is intended to fulfill the 6mm SAW requirements, being a round that performed as well as the 7.62mm NATO at long ranges but could be used in a 5.56mm sized rifle and be shared between the LMG and assault rifles of the squad. In addition, the firearm fills the gap left by the 5.56mm's poor terminal performance. While the 5.56mm is adequate at close range, past 300 yards the round suffers dramatically, losing most of it's power and accuracy and additionally failing to tumble and fragment under 760 m/s. According to reports by the U.S. military, the 5.56mm failed to perform as well as the military was hoping at ranges of 300-600 meters, and has roughly 50% of engagements in Iraq and Afghanistan were between 300-900 meters, this became a pertinent issue for the U.S. military. The M14, a weapon chambered in the 7.62mm NATO, was reintroduced, but due to it's heavier weight, poorer maneuverability and lack of standardization with the 5.56mm, created issues being integrated in to the squad. Instead with the 6.2mm caseless round, the round can now reach these ranges with relatively little problem, allowing every soldier to be potentially be a marksmen, and the machine gunner to suppress out to long ranges, the same as the 7.62mm NATO cartridge. The 6mm round has more energy than the 7.62mm NATO at 600 yards, and a flatter trajectory, reaching a maximum height of 3 foot above the target along a 600 yard trajectory. At 1000 yards the round only reaches a maximum height of 8 feet, which is less than the 7.62mm NATO at 850 yards with 10 feet, or the 7.62mm NATO sniper round of 10 feet at 1000 yards. However, the weapon drops off rapidly after this, increasing the maximum height of the cartridge to 12 feet at 1200 yards. Compared to the 6mm SAW cartridge, it uses a heavier bullet and has slightly more power, utilizing .25-45 sharp gun powder and 35 grains of powder instead. By using the same powder in the 6.2mm casless round, the cartridge is much smaller than it's power would otherwise suggest, and it allows for a cooler, cleaner burn. The powder is also the same type of caseless powder and binder used in the LSAT series of weapons, being smaller, lighter and less prone to overheating and cook-offs than most caseless weapons.
The weapon uses a detachable polygonal cobalt chrome gain twist "flow formed" 3 groove 1:7 inch (1 complete turn in 1 in 7 inches / 180 mm) right hand turn barrel; the barrel is made of an alloy that contains more than 50 percent cobalt. The barrel is roughly 13% heavier than standard steel barrels, but is more erosion and corrosion-resistant and is designed to retain high strength during long-term exposure to high temperatures. Cobalt alloys are frequently used in the aerospace industry, such as the hot-gas section of turbine engines. A proof of concept M240 7.62mm x 51mm NATO barrel, in practice, had 24,000 rounds test-fired through it, causing it to reach temperatures of 1,100 degrees, without failure. A steel barrel would have failed under such treatment. The gain twist not only enhances the accuracy of the weapon, but also dramatically increases it's life. As the first 4 inches and last 4 inches of the barrel receive the greatest wear, the gain twist allows a more gradual application of the rifling, thus providing less friction to the bullet and the barrel, which both increases accuracy and durability, as well as the velocity of the bullet. The barrel itself, combined with polygonal rifling, is extremely durable, and has a minimum 30,000 round barrel life, although it is possible to extend this or get use out of the rifle after the minimum is reached. In addition to this, the barrel is cryogenically treated, making it harder and thus slightly more durable. The weapon resultingly has high accuracy, achieving approximately 1 MOA, and good durability nad heat resistance for sustained fir use. The barrel is detachable in a mechanism similar to the Tavor, but uses locking lugs on both sides of the barrel, and is optionally quick detachable. Quick-detachable barrels, like on the Steyr Aug, are generally inaccurate, possessing around 4.5 MOA, which etheir requires precision made parts (like on a machine gun) to compensate or poor accuracy in order to operate. As a result, like the Tavor it has a locking mechanism to keep barrel tight within the weapon, but it also can be fitted in the weapon without these tightening mechanisms. This gives the option of having a quick-detachable barrel or a slow detachable barrel, thus allowing for the ability to swap barrels quickly in combat with LMG or SAW variants of the weapon, but be tightened if better accuracy (such as with a Marksmen weapon) is desired.
The weapon uses a muzzle break which contours with the rifling grooves of the barrel and is tightened in the barrel to retain the weapon's barrel harmonics, like with the FR F2. This muzzlebreak prevents the disruption of the gyroscopic stability of the rifling imparted normally by muzzlebreaks, reducing accuracy problems that are often associated with them. Thus the muzzlebreak not only reduces the recoil by approximately 40%, but also increases accuracy over normal firearms. The muzzle break essentially dampens barrel vibrations and reduces the felt recoil, and the muzzle ports matches the grooves the rifling in the barrel which helps limit distortion to the projectile as it's leaving the barrel. Combined with rotating cylinder and lack of moving parts while firing, the recoil of the weapon is rather low, and slightly lighter than a 5.56mm weapon. This helps the weapon maintain controllability under high volumes of fire. The weapon has 2 inches of adjustability in the stock, which allows it to fit to the shoulder and gear of an individual soldier, but is much stiffer than most adjustable stocks, serving as a good platform for accuracy. The weapon possesses an ambidextrous 3-position safety and a non-reciprocating bolt handle on the top of the firearm, as well as an adjustable cheek weld with an additional kevlar pad underneath it to protect the soldier's face in case of a catastrophic malfunction in the firearm. The trigger is 5.5 pounds, relatively light for a bullpup and crisp, using an incredibly smooth and deburred trigger system to reduce the pull weight and make it easier to rapid fire with. The weapon performs remarkably well out to 600 yards, being far superior to the 5.56mm in terms of power and barrier penetration, as well as the 7.62mm NATO round. The smaller diameter bullet with high energy can penetrate armor better than the 5.56mm or 7.62mm at 600 and 1000 yards, and does better than the 5.56mm even under 100 yards. The weapon has 45% more power than a 5.56mm and 30% more power than an Ak-47 at the muzzle, with a round roughly the same size as an Ak-47, giving it good barrier penetration and stopping power. The round shares commonality with the machine gun of the squad, thus reducing logistics problems for the military.
