The study found that the M16A1 was great, but could be improved ... It eventually began a long-term project to develop an advanced combat rifle that could potentially use a new, radical ammo ...

Back in 1965, the Army officially adopted the initial version of the 5.56x45mm AR-15/M16, the M16A1 rifle; a design that has retained several core aspects, despite significant evolution ...

When actually fielded in the mid-1980s, the SAW was issued as a one-for-one replacement for the designated "automatic rifle" (M16A1) in the Fire Team. In this regard, the SAW filled the void ...