The story of 5.56×45mm self-loading rifles in Iran goes back prior to the Revolutionary-era. During the modernization efforts conducted by Mohammad Reza Shah Pahlavi to improve Iranian Armed Forces Capabilities, numerous 5.56×45mm rifles were tested. Among these rifles that are documented and tested by Iranians were FN CAL and AR-18 assault rifles. But the program didn’t adopt a new rifle and it ceased when Islamic Revolution occurred in 1978. In this article we will examine the history of Iran’s 5.56×45mm rifles.