Question: when did the assault rifle become available to the public

title: Assault rifle
text: In March 1970 , the U.S. recommended that all NATO forces adopt the 5.56 × 45mm cartridge . This shift represented a change in the philosophy of the military 's long - held position about caliber size . By the middle of the 1970s , other armies were looking at assault rifle type weapons . A NATO standardization effort soon started and tests of various rounds were carried out starting in 1977 . The U.S. offered the 5.56 × 45mm M193 round , but there were concerns about its penetration in the face of the wider introduction of body armor . In the end the Belgian 5.56 × 45mm SS109 round was chosen ( STANAG 4172 ) in October 1980 . The SS109 round was based on the U.S. cartridge but included a new stronger , heavier , 62 grain bullet design , with better long range performance and improved penetration ( specifically , to consistently penetrate the side of a steel helmet at 600 meters ) .