[betterunix]

If I remember my history correctly, assault rifles replaced "battle rifles," which were similarly designed but fired much heavier and more powerful cartridges (and were necessarily larger and heavier). The way I learned it, armies discovered that typical infantry engagements were at distances of hundreds of yards, rather than the mile-long distances guns like the M1 Garand could fire at, and that the weight of the ammunition and recoil of the guns were making soldiers less effective.