Why is it that on pretty much all of the weapons that the U.S. army uses they have an 'M' infront of the name.
Some examples being: M16 Assault Rifle
M4 Carbine
M203 grenade launcher
M249 SAW light machine gun
M9 pistol
M1014 Combat Shotgun
M107 Sniper Rifle
At first I thought the 'M' meant that they were made by Colt cause of the M16 and M4 being made by them which made me think on why would they only use guns by Colt so I looked these weapons up and found out they were made by different companys and most had different names.
So my question is what does the 'M' stand for?