FWIW: In 1979 when I was still fairly new to LE, I worked for an agency that had no written policy regulating the type of duty weapon their officers carried, as virtually all were individually purchased. For a couple of weeks, I decided I'd carry a Ruger Old Model ("Flat-top") Blackhawk in .44 Magnum, with some 250 grain SWC Special loads (900 fps), in a Roy Baker "Pancake" holster. I carried extra ammo in a dump pouch. I only chose this revolver out of nostalgia, and voluntarily switched to more modern/practical duty weapon(s) not long afterwards.

Just thought I'd bring this up, because even though I retired only ten years ago, I haven't met another officer that carried a single action revolver (within policy) before or since!

ETA: About five years ago, I noticed a deputy sheriff with the Santa Barbara County Sheriff's Department in court, carrying a S&W Model 627 (eight round capacity). He had a duty rig with four spare reloads.

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I'm not fluent in the language of violence, but I know enough to get around in places where it's spoken.