Gunshot recordings: Copyright (c) 2009 Vincent (Vince) Sevedge.
Source: Gunshot Sounds, uploaded by Tabasco, OpenGameArt.org
https://opengameart.org/content/gunshot-sounds
Original archive: https://opengameart.org/sites/default/files/sounds.zip

Used under the archive's Creative Commons Attribution 3.0 Unported license:
https://creativecommons.org/licenses/by/3.0/
(The listing also offers CC0; this project retains attribution and the archive license.)

pistol.wav: extracted first CZ-52 shot, trimmed, converted to mono, tail faded.
machine.wav: extracted first SKS shot, trimmed, converted to mono, tail faded.
Playback adds small pitch variations and a quieter reflection.