Weapon Name- M7, M12, M13, M288, M488, MXL1200
Round Type- 4.7mm, 6.8mm, 7.8mm, 10.2mm
Over-all length- 23 inches, 28 inches, 31 inches, 35 inches, 46 inches
Barrel length- 13.5 inches, 18 inches, 20 inches, 22 inches, 29 inches
Weight- 5.5 lb, 6.2 lb, 6.8 lb, 7.9 lb, 19.2 lb
Rate of Fire- 550 RPM, 210 RPM, 250 RPM
Feed Mechanism- Detachable box magazine, tube fed, belt fed
Round Capacity- 30, 62, 1-4 grenades
Effective Range- 300-600 meters
Range- 1200 meters, 2100 meters
Accuracy- 1.5 MOA, 1 MOA
Accessories- Picatinny Rails
Quick switch firing mechanism- Extra trigger
Scope/Sights- Picatinny rails, Thermal vision scope
Muzzle Velocity- 750 m/s (13.5 inch barrel), 18 inch (820 m/s), 20 inch barrel (850 m/s) - 320 m/s grenade - 1100 m/s .408
Firing System- Long stroke gas piston, electrically ignited system
Miscellaneous/electronic information- The M12 series of rifles resemble a bullpup m14 in design but have design features from both the Philippine series of rifles and the Stoner 63. It utilizes a "constant recoil principle" action in order to decrease felt recoil, a long dwell time, and longer gas cushion reminiscent of a gas tappet system to help reduce felt recoil. Despite being similar to the mini-14 design, it's closer to the M14 in design in that it is a long stroke gas piston and not a short stroke gas piston design.
Basic Information
The bullpup M12 series of rifles are the primary firearms of the Manokan military (a fictional military) based around a constant recoil principle firearm similar to the Ultimax 100 or Stoner 63, combined with the fire mechanism of the M14. The mechanism of the m14, which is similar the M1 carbine, Mini-14 and M1 garand was chosen due to it's relatively small overall size for it's caliber, being short and light-weight with a minimalist design, and it's relatively robust nature. At 6 pounds and 35 inches long with an 18 inch barrel, the mini-14 is quite small for even a 5.56mm rifle, and the M1 carbine was only 5 pounds and 35 inches long with an 18 inch barrel as well. The small overall size combined with it's short overall action (around 7 inches) made it ideal to convert to a bullpup firearm. A 1 to 1 conversion is impractical given the forged or cast nature of the receivers of these series of rifles, and so it was heavily modified for use with the M12. The weapon is also not parts compatible with any of these rifles despite it's overall similarity.
It is largely designed to be chambered in the aluminum cased 6.2mm x 39mm cartridge, which is itself similar to the 6.5mm grendel. The cartridge utilizes a fast burning propellant, similar to those found in the .300 black out or 6.8mm remington, allowing it to achieve a high level of power even from a short barrel. The case is also designed to fit inside of the majority of 5.56mm size rifles, and use comparable magazines. Although the cartridges will fit inside of any standard 5.56mm magazine, it slightly wider and causes magazines to bulge, only fitting 26 rounds in a standard 30 round magazine, and therefore slightly extended magazines with metal feed lips so they don't bulge is necessary for reliable operations. The manokan military produces it's own proprietary magazines based on magpul PMAG's with steel feed lips and magazine retention parts to both increase the strength and stop bulging. These magazines can easily fire both 5.56mm and 6.2mm rounds reliably, however other 5.56mm magazines may not function well with 6.2mm cartridges. With a simple barrel swap, the firearm is capable of seamlessly transitioning between 5.56mm and 6.2mm cartridges, which is why the round was chosen. It offers greater power, range and accuracy than the 5.56mm, as well as armor penetration, having a much higher ballistic coefficient, and being close to the ideal "6mm optimum" power levels which were sought after by the U.S. military in various experimental weapon designs. It has a very high level of energy despite it's overall short barrel length, good stopping power and range, and a high sectional density, which increases both the armor penetration and aerodynamics of the round. It retains it's energy and improved armor penetration even at very long ranges, unlike the 5.56mm which drops off quickly despite it's good armor penetration at close range. The muzzle velocity of the 6.2mm is lower than the 5.56mm, but is higher at long ranges despite this. The 6mm round offers slightly better performance than the 6.5mm grendel in terms of armor penetration and aerodynamics and so it was chosen.
