5-inch/54-caliber Mark 45 gun

The 5-inch (127 mm)/54-caliber (Mk 45) lightweight gun is a U.S. naval artillery gun mount consisting of a 5 in (127 mm) L54 Mark 19 gun on the Mark 45 mount. The later 62-calibre-long version consists of a longer-barrel L62 Mark 36 gun fitted on the same Mark 45 mount.