The M16 was America's first successful assault rifle. It had a lightweight frame, the ammunition it carried was both accurate and light, and it could be outfitted for most roles. In the early years however, the M16 had problem due to the ammunition it used plus it frequently jammed in a firefight. Upon the arrival of the M16A2 and up, the M16 became a great hit, as it allowed US marines and army personnel better firepower than most armies.