(set in 1920?, written in 1923, published in 1924)
That scream had roused me to action, and in a second I had retrieved my automatic and emptied its entire contents into the wolfish monstrosity before me. But I heard the unhindered thud of each bullet as it imbedded itself in the opposite wall. My nerves gave way.
This cooperation with Clifford Eddy mentions a “guardian automatic” carried in the pocket of the unnamed narrator. Considering how light he travelled, with his money in his belt and lunch in his hand, we can again assume that it was a smallish pocket weapon rather than a big .45, perhaps a Colt Pocket Hammerless pistol (Investigator Weapons 1: The 1920s and 1930s, pp. 40-41) in .32 ACP (7.65×17mmSR Browning) or a Colt Vest Pocket Hammerless pistol (Investigator Weapons 1, pp. 43-44) in .25 ACP (6.35×16mmSR Browning).
While the narrator’s bullets had no effect on the ghost-like appearance of the werewolf, we learn that a living werewolf can be killed with ordinary weapons, since the good people of Maine “filled it full of lead and buried it in the house” back in the 1860s. In the game, however, werewolves are “immune to most weapons” (Call of Cthulhu, Sixth Edition, p. 210, and Call of Cthulhu, Seventh Edition, pp. 334-335).