From the preview:
Extensively used in Vietnam, the M113 proved to be a solid workhorse capable of breaking through heavy jungle and transporting infantry through to enemy positions.
The mechanised infantry were organised the same as normal rifle platoons with two exceptions. The most obvious was the provision of M113 armoured personnel carriers, known as ‘tracks’ to their crews. Less obvious, but more important in many operations was the addition of an M60 machinegun to each squad. This was a significant boost in firepower, especially when combined with the usual M16 rifles and M79 grenade launchers.