https://www.urbandictionary.com/define. ... k and loadlock and load
(verb expression) Short for locking the magazine/cartridge into the gun and loading the ammunition into the gun's chamber. (Usu. used to show toughness, ambition, fear and other strong characteristics. Originally spoken by John Wayne in "Sands of Iwo Jima" as "load and lock".
So is the above definition incorrect or does "lock" mean different things in different expressions?