SG-40: The Schiene Gewehr 40/ Rail Rifle 40 is the main weapon of the Weltraumrepubliken, a union of European colonies who obtained their autonomy. With a diverse population, German became the main Lingua Franca for both commerce and industry, eventually becoming the De Facto political one. The first rail rifle made for individual soldier, it was designed around the wear of the electromagnetic rails, which could sustain 2000 rounds before showing signs of degradation. This led to the creation of the Habafa 95, an intermediary battery between the GWEN and M-18 ones, it was technically capable of firing the 2000 rounds but environmental effect could drop it efficacy down to 1500 rounds, so it was easily removable, with the soldiers being issued one in extra. The munition was a standard 9mm balanced winged steel flechette accelerated by two vertical electromagnetic rails, the munitions were loaded in a standard magazine with a capacity of 30 rounds.
A good, balanced and affordable weapon, the SG-40 would however be marred with some issues. The first and more well known was the desire to create a "sealed" weapon, meaning that it should fire without opened part, this meant that the ejection lever, which served to eject misinserted munition, had to be covered even when resting. While the Weltraumrepubliken engineers designed an ingenious "scaled" cover, it was well known to jam and lock, especially if the rifle had been roughed, leading to many soldiers illegally modifying the weapon to remove it.
An other issue was the barrel, if in the acceleration chamber it was a smooth bore to not disturb the rails, it received a polygonal rifling in the extension. The goal was to give the munition a spin to stabilize it but tests on the field showed that the "wings" on the flechette, needed to connect the two rails, were giving good enough ballistic for the usual combat range. This sudden rifling often caused problems with faulty, weakened, munitions with part of them breaking up in the outer barrel or, in rare but critical incident, jamming inside the barrel.
But despite these flaws, the SG-40 had proven time and time again to be a reliable, if over-engineered, piece of equipment, showing that even in space, the proud descendant of the old continent maintained the famed "Deutsche Qualität".