Yes. Aside from the US, they're also made under license in Canada, Georgia, Malaysia, and the Philippines.
m4 rifles and Steyr AUG
If you are referring to the U.S.A. Armies standard weapon for infantry it is/was the range of M16 Assault rifles. Now they are being phased out and replaced with M4 Carbines.
If you are talking about things like M4 and M16 then those are just the names of different types of rifles.
M16A2 & M16A4 rifles and M4 series carbines.
the top 3 rifles in the american military are the M4, the M16 and the M14
The M4 is an assault rifle based off it's popular cousins the M16 and AR 15 also assault rifles.
The CAR-15 family of carbines are based on the M116A1 rifle, whereas the M4 is a development of the A2 series rifles. The lineage of the M4 naturally leads back to the CAR-15, but it is not marketed as a CAR-15.
Couple reasons, one being doctrinal differences between units. Another reason being is that some of the M16 rifles are special purpose weapons, intended for unit sharpshooters and the like.
The M16 and the M4 are the US designations for the AR-15 pattern of rifles.
Videos of how to assemble an M4 Airsoft rifle can be found at YouTube, as it is always easier to see how to do such an assembly than to read it. Rifles should always be kept away from children.
Colt's Manufacturing made the majority of the M16 rifles, and all of the M4 rifles, purchased by the US military. Fabrique Nationale would come in second, providing some of the M16 rifles, and all of the M249 and M240 machine guns.
The U.S. military primarily uses the M4 Carbine, which is manufactured by Colt's Manufacturing Company under the designation M4. The M4 is a gas-operated, air-cooled, magazine-fed carbine that is widely used by various branches of the military. Other manufacturers, such as FN Herstal and Remington, have also produced M4 variants under military contracts.