Here is a link to a video of some long service NCO types discussing machine gun theory and employment. At 47:40, they begin talking about how squad and fire team tactics affect the type of machine gun used, and vice versa. They also touch on the utility of a three team Marine Corps squad, vs a two team army squad.
Most interesting to me was the rant that begins at about 54:00, where Chuck Pressburg describes how US infantry squads were forbidden to use fire and maneuver at the team level. It is a glimpse at how small unit tactics maybe died out in the US military.
The whole video is almost five hours, but if you have the time it is worth listening to. The discussion is wide ranging and multidimensional, covering tactics, training, fitness, as well as the weapons themselves.
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