lock and load
Originated in American English, supposedly as an instructional command to prepare an M1 Garand, the main rifle used during World War II, for battle, though it is disputed if the phrase was actually used this early. It was used in 1949 by John Wayne in the movie Sands of Iwo Jima. Various similar phrases predate it, including in transposed form as “load and lock”.
- The most common theory connects this order to the operation of the M1 Garand rifle. Before loading the ammunition clip into the rifle, the operating rod handle is pulled to the rear until the bolt is securely locked open. According to the M1 Garand Manual, loading the clip without first locking the bolt could result in an accidental discharge of a round. In the 1943 training film (Rifle Marksmanship with M1 Rifle) the instructor orders first "Lock" then "Load".
- A transposition of "load and lock" - to load the ammunition clip into the rifle, then to lock the bolt forward (which forces a round into the chamber, readying a rifle for firing).
- Condensing the M-16 firing preparation commands of "LOCK a magazine in the magazine well, then LOAD a round into the firing chamber by pulling the charging handle to the rear of the weapon."
- The use of flintlock rifles, which required the hammer to be locked back at the half-cock position before placing primer in the pan.
- Alternatively, a Sporting Magazine from 1821 had the complete flintlock expression as "brush the dirt away from the lock, and load ...".
- From artillery usage: to 'lock' a gun into firing position before loading.
- (US, slang) A command to prepare a weapon for battle.
- (US, slang) Prepare for an imminent event.