"World War II, the most mechanized war in history, was fought with a profusion of complex, formidable weapons which radically affected the course of events in our century. It is nearly impossible to understand the war-to read its history or the memoirs of it participants, or even to watch documentary films about it-without some knowledge of the terrible machines with which it was fought" (Kirk and Young, Preface).
Many new small arms were developed during World War II, the most notable being the new improvements on the machine gun. Both Axis and Allies developed scores of new weapons to meet an ever-growing demand. In World War I, it had been shown that heavy machine guns could be successful against tanks; however, "by 1939 most tank armor had become thick enough the be proof against even the largest machine guns (the firing bullets approximately a half inch in diameter) and a majority of the great powers lost interest in the big guns" (Kirk and Young, 292).
The major exception to this was the United States. American soldiers used the heavy Browning .50 caliber M2 in almost every aspect of fighting. The Army used the M2 primarily as a defensive weapon of its infantry forces. The armor divisions used it as a second armament in many combat vehicles. Army and Navy Air Forces (the U.S. Air Force had not been formed yet) used the M2 almost to the exclusion of all other machine gun. All forces used the M2 as a light anti-aircraft weapon. All told, about two million M2's were produced during the war (292). .
The U.S did not just like big guns: there were very convincing arguments to the superiority of the M2. It had many of the good points of smaller caliber arms, plus great range, accuracy, and the incredible stopping power of its big bullets. The M2 was belt-fed, "cycled at about 450 round per minute, had a maximum range of 7, 200 yards, and had a muzzle velocity of 2, 660 feet-per-second" (292).