The M16 Assault Rifle is the standard issue shoulder weapon in the US military. It marks a departure from normal ballistics in that it uses a smaller, high-velocity round (5.56 mm caliber vs. 7.62 mm). This results in a smaller and lighter weapon as well as smaller ammunition, significantly decreasing combat load.
The M-16 was effective at ranges of less than 400-460 meters, the range within which United States experiences in World War II and Korea had indicated that small arms engagements would occur. The weapon permitted the heavily burdened soldier to maintain the same degree of firepower at a reduced weight. And finally, the M-16 allowed every soldier to have an automatic fire capability whenever the situation required it, while the weapon's lighter ammunition facilitated battlefield resupply in greater quantities, enabling the resupply of field units for longer periods of time.
While the M16 possessed less "stopping power" than the M14. But it was more accurate due to the reduction in recoil stemming from the smaller proiectile fired. Both the M16Al and the AK-47 rifles were judged far more effective than the M14 in terms of expected casualties per combat load. In general, they produced two times the number of combat casualties that could be produced by the M14. Thus there was clear evidence of military utility in the M16 rifle, resulting in an increased degree of military advantage accruing to its user.