In the chaos of combat, you might not know where the enemy is. Especially with the advent of a new enemy in the United Equestrian Conclave, but with enough firepower, you can always make them keep their heads down. In the early twenty-first century, it was thought that the modern rifle has thirty rounds and is forged from iron and furnished in plastic. It should kill a man in a single shot and kick like a rabbit, and be as reliable as the AK-47 in the process.

This one rifle however, is different, the M-66 is the definitive weapon of the North American Commonwealth, it dares to break tradition in the face of modern warfare, controversial at first it managed to shed its bad reputation and became an institution. So why did the NAC abandon their 5.56, what problems did this design face, and what makes it perfect for use in the modern age over one hundred years after its introduction?

The end of World war three changed everything, traditional tactics, were outmoded, combat was faster paced, closer range, but everyone wore body armor that could block the others rounds. This meant that combat was not just about volume of fire, but armor piercing ability and accuracy.

Misriah Armory was founded in 2052, as a division of Wayland-Yutani. And their premier rifle design was lead by american small arms designer Avery Johnson, in response for the newly formed NAC's need for a new rifle the AR-50 was developed. Its bullpup design, polymer body, titanium receiver and ability to link with armors computer made for a truly modern platform. At first, the weapon was designed to be used with the old 5.56x45 used by its pressor, but these rounds proved to be almost useless against modern ceramic ballistic hardshell.

But with inspiration from the development of the NAC PDW the MP-15 and its ammunition, came the use of the 10mm caseless flechette. The tungsten flechette's ability to go straight through conventional battle armor and devastate flesh while being much smaller than the 5.56 changed everything. So with a change to the weapon's receiver, the advent of internal cooling, and the addition of a larger magazine it allowed the user to carry 250 rounds in a magazine that now fit snugly into the butt of the weapon. The rifle known as the Misriah Armory AR-50 was adapted to fire this smaller cartridge and under Misriah's patronage, the rifle was adopted by the NAC's military in 2066.

With a new home came a new designation, the M-66. There would be no delay before the rifles first tiral, under the chalenging political conditions of the race to colonize space, deployed during the first Mars war. Mars was a taxing envirornmet, martion dust would get into the internals, leading to jamming and the weapons lack of grenade launcher lead to the weapon being hated bt those it was issued to, forcing the users to cary a second weapon.

On top of this some parts were suprisingly fragile, and without diligent maintanence stopages and failers were fequent. But perhaps the worst thing was the weapon that was designed to be used on earth, would fail to fire in a complete vacuum, a deadly shortcoming, given the thin atmosphere of Mars. Compared to the SRA's own flechette rifle the S-MAG it would fall short almost every time.

So, to combat this the designers at Misriah took this new information to heart, and took the M-66 to the drawing board. And after a year of R&D and pressure from the NAC they integrated a grenade launcher into the weapon's casing, sealed the internals to allow it to work in a vacuum, reinforced the fragile portions and added an integrated targeting laser and more attachment hardpoints.

With this, the designers at Misriah had thought they had created a weapon that would allow an NAC trooper to beat someone to death with its weight, suppress a threat, or be a marksman. But what they really made was something that could withstand the test of time. During it's over a century of service soldiers of the NAC's Defence corps would respectfully call it "The 66". And "The 66" still sees servase to this day in the war againced the UEC, being standard issue to NAC space born Infintry, and Homeworld Defence.

It'll work on the land, under water, and in space. Over a century of aiding the NAC and her interests. The M-66, an American classic, a weapon for the modern age, reliable, deadly.

This is fine and all but what does it have to do with ponies? Or Humans in Equestria?

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It is one of the standard issue weapons used against the UEC, the equestrians.