The general types of practice bombs are sub-caliber or full scale practice bombs. Subcaliber means that the practice bomb is much smaller in size and weight than the service bomb it simulates. The MK 76, MK 106 and BDU-48/B are subcaliber practice bombs. The BDU-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 LDGP bombs are used extensively for practice bombing. These bombs are physically the same as the MK 80 series LDGP 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.