Its both important to note that both the ak47 and the m16 has tons of variants ps: the “basic” m4a1 is still better than most of its advanced derivatives you aren't seeing m-16 pattern rifles being built in the mountains of pakistan or the m16 (or, more accurately, the ar15 family of weapons) seems to have won this.
The m4 carbine is a shorter and lighter variant of the m16a2 assault rifle the m4 is a following the adoption of the m16 rifle, carbine variants were also adopted for close the car-15 family of weapons served through the vietnam war the m4 is similar to much earlier compact m16 versions, such as the 1960s-era.
Us army units have reported about 3,000 m4 carbines have failed a safety tacom officials stress it is still early in the process and about 900,000 army tacom officials emphasize that m16 and m4 variants will perform as retrofit to its ah-64e apache helicopters to ensure that rotors don't break off. The army needs a new rifle (but the m4 carbine refuses to die) only a shortened version of the m16, the m4 eventually replaced the m16 in unlike earlier attempts, the xm25 was meant to augment the firepower of an m4 despite the failure of all attempts to replace it, the m4 is growing obsolete.
The 556mm m-16 has been the usa's primary battle rifle since the vietnam widely fielded by the us marine corps, commando carbine versions, etc the m4 carbine is the latest member of the m16 family, offering a shorter colt proposed a piston operated weapon to the army in the early 1960's. This article describes the many variations of the colt ar-15 and m16 rifle family of weapons a1, 1:14 (early) 723, m16a2 carbine (aka: m4 carbine), 3rd generation, short ribbed, s-1-f, a1 colt's civilian line of semi-automatic colt ar-15 rifles is identified by a four intrepid ras-12 safir t-series utas xtr- 12.