You can not unlock this weapon except by modding your Xbox 360 or PS3.
Go to this website it shows all the weapons that have the Golden Camoflauge:'
http://callofduty.wikia.com/wiki/Golden_Camouflage
There is an M4 carbine in Call of Duty: Modern Warfare 2.
M855 62 grain ball.
5.56 nato or civilain 223 remington
The M4 CARBINE IS BETTER THAN THE M16.
Security Forces are Arming Group A- Regular use of weapons as duty requirement. Primary Duty weapon is M4 Carbine.
No one will give you an M4 rifle/carbine for free.
M4 is the carbine- shorter barrel
Go into multi player, then create class. select gun, i highly recommend the M4 carbine. a side arm dessert eagle and perks u have to reach a certain level to be able to make one. then press O. DONE
Walmart get the m4 (same thing) field duty kit. It's m4 with m1911 pistol grip and red dot site 100$
The Colt M4 Carbine .22 is a replica of the real M4 but in .22 caliber.
m4,m16,ak47
The M4 carbine has a muzzle velocity of 2,970fps(884m/s).