Old School (Pixiv Fanbox)

They call him "Old Man". Not because he's old, but because he insists on using old things, such as his .44 magnum revolver. If he had a dollar every time he heard about how such and such energy pistol is more flexible, powerful, accurate and/or reliable, he'd... well, he wouldn't be able to do much after a century of inflation. Still, the detective clung to his guns, literally. (Unrelated gropey monster variation) The expected outcome plus the rest of the story on discord!