The expression “lock and load”, we often say that before preparing to do something dangerous. Though where does the expression come from? And what did it actually mean before the current sense. It all spurred from the American G.Is during the Second World War. They said the expression when they loaded their M1 rifles prior to a tough task. The phrase has a simple meaning, inserting a full ammunition clip then lock the bolt straight, pressuring a round into the chamber. The initial expression was “load and lock” but when the All American, John Wayne mixed the words up a new expression was born in the English lexicon “lock and load”. John Wayne had mixed up the expression in the movie The Sands Of Iwo Jima, the expression has stayed since.
Did you know in the movie The Sands Of Iwo Jima, John Wayne and the rest of the characters did get to reinact the famous scene of rising the American flag on Mount Suribachi. The real great detail about that is, they did use the original flag that was mounted. They had to borrow it from a Museum in Virginia.