The M16 and its variants have been mainstays for the US military for decades.

Before the M16, however, US troops used a variety of other rifles in some of the 20th century's most destructive battles.

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Throughout history, the US military has used a wide variety of guns to win its battles.

Prior to the M16, there were several weapons used across the service throughout some of the most devastating wars the world has ever seen.

Here are some of those weapons: