The M-50
The Sub Assault Rifle is a weapon slightly smaller than your average Carbine,That fires an ammunition that is hybridized with either the length and width of the Assault Rifle or Submachine Gun's ammunition,In turn making it a whole new weapon.
M-50
The very first Sub Assault Rifle ever designed was the M-50,A Sub Assault Rifle with pin point accuracy and the manuverability of the P90 Submachine Gun.This weapon also uses a new and improved ammunition,The 5.56x19mm NATO (A hybrid between the M-16's 5.56x45mm NATO and the MP40's 9x19mm Parabellum) and it is just as powerful.The weapon also utilizes a secondary select system,Which instead of switching fire modes,It switches between the either activation or deactivation of the barrel's built in suppressor.
After The M-50
The M-50 paved the way for a new form of Assault Rifle,Sooner or later,The German MG-52 came out and soon after,The British ML-101 was born.