What is small caliber ammunition?

Some articles on small, small caliber ammunition, caliber:

Lake City Ammunition Plant - Capabilities
... Capabilities of the plant include Small arms cartridges components such as percussion and electric primer pyrotechnics small caliber ammunition (5.56 mm 7.62 mm.50 caliber and 20 mm) performs ...

Famous quotes containing the word small:

    All the way home I kept remembering
    The small book in my pocket. It was there.
    Robert Frost (1874–1963)