I've seen model 10s and 586/686s worn by more than one in "a near-by county" (in WA). The cop I spoke to said "unofficial" policy (which is why I'm not identifying the LE agency) was that if they owned them, they could wear them. Since the county's official arm is an older 9mm, which apparently isn't trusted, the trusty revolver is still preferred.

Keep in mind, this is a county in which there is only one incorporated "city" and lots more trees than teeth......