This war-movie standard phrase has always annoyed me. It even showed up in "Reluctant Lieutenant," a book I’ve been reading, purporting to have been used by sergeants on Basic Training firing ranges at Fort Dix, NJ in 1967. Bothers me, I say, because it’s not obvious to me how one could lock first and then load. But loading first and then locking the rifle’s bolt forward makes sense.
Indeed, the original order was to load and lock and it comes from the M-1 Garand Manual here, the standard rifle of the second world war. But Wikipedia says lock and load also makes sense in terms of locking the bolt back before loading the round into the chamber. In any case, they attribute the current usage to John Wayne in the movie "Sands of Iwo Jima" in 1949. So I suppose it could have been used that way at Dix eighteen years later, and ever since.
THE TEXAS SCRIBBLER 