Doc Single Shot Pistols

"We'd better be moving," Doc said at last. "First, we will visit the neighborhood of the hot mud lake, on the chance some supplies might have spilled out of our plane. In case you haven't noticed it, we're practically out of ammunition."

The others hastily examined their guns. They found only a few cartridges in each weapon. Monk, naturally the most reckless, had but four cartridges left.

"Throw the lever which changes your guns to single-shot operation," Doc directed. "We've got to count every bullet. Although the weapons are virtually useless against these prehistoric monsters, they will be effective upon Kar."

- The Land of Terror (1933) Chapter 18