You can buy a plastic m4 or you can buy a metal m4
Almost everywhere, the answer is no.
no it isn't but it has very hard plastic
their both machine guns so yes
M16A2 & M16A4 rifles and M4 series carbines.
The M16. The M16 entered production in 1960. The M4 entered production in 1984, and was an improvement over the earlier XM-177 carbines.
The only actual M4 carbines are manufactured by Colt and companies licensed directly from Colt. The M4 is made in the USA, Georgia, Canada, and Malaysia.
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.
Sig Sauer P228, in 10x22 (.40 S&W) is the standard sidearm. They may also be equipped with M4 carbines.
Carbines, being a type of firearm, usually have the barrel and action made of steel and stocks made of either wood or plastic.
There is no, "CQBR MK16" version. If you are referring to the "MK18" version, then yes. It has a version 2 gearbox that is all metal; however, the hop up is plastic.
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.
A carbine is simply a shorter version of the long gun. If the long gun was rifled, the carbine version would also be rifled. Examples of well known carbines with rifled barrels include the M1 Carbine of WW 2 and the M4 carbine version of the M16.