How did the development of assault rifles change infantry combat during World War II?

During World War II, the development of the assault rifle introduced a transformative concept to infantry combat, though its impact was limited by the timing of its deployment. While most infantry units during the war relied on bolt-action rifles, the German introduction of the Sturmgewehr 44 (MP44) pioneered the use of an "intermediate" power cartridge—lighter and less potent than standard rifle ammunition—paired with a selective-fire mechanism.1

This design allowed soldiers to maintain a high volume of fire with manageable recoil at effective combat ranges, bridging the gap between the limited rate of fire of bolt-action rifles and the heavy, unmanageable nature of earlier automatic weapons. Although only about 425,000 to 440,000 Sturmgewehr 44 rifles were produced—too few to alter the outcome of the German war effort—the weapon established the fundamental design philosophy for infantry arms that would dominate the post-war era. By demonstrating the tactical advantages of a lightweight, portable, and selective-fire weapon, it set the standard for modern infantry combat, eventually leading to the widespread adoption of rifles like the AK-47 and the M16.1