Practice bombs are used to simulate the same ballistic properties of service type bombs. They are manufactured as either solid cast metal bodies or thin sheet metal containers. Since practice bombs contain no explosive filler, a practice bomb signal cartridge (smoke) is used for visual observation of weapon target impact. Due to the relatively small amount of explosive material in practice bombs (small signal charge), these items are a danger if they have not cleared E.O.D.

The general types of practice bombs are sub-caliber or full scale practice bombs. Sub-caliber means that the practice bomb is much smaller in size and weight than the service bomb it simulates. The MK 76, MK 106 and B.DU-48/B are sub-caliber practice bombs. The B.DU-45 inert loaded bombs are full scale practice bombs. Full scale practice bombs are representative of service bombs in size and weight.

Although not classified as practice bombs, the MK 80 series inert filled L.D.G.P. bombs are used extensively for practice bombing. These bombs are physically the same as the MK 80 series L.D.G.P. service bombs except that they do not contain any explosive filler and are painted blue (may be olive drab color with blue stripes). These bombs provide training for assembly and loading crews, as well as training for the pilots.