As of last year the Illinois Department of Corrections was carrying Smith & Wesson Model 64 double-action .38 Special centerfire stainless steel K-frame service revolvers. I spotted some corrections officers with them at a southern Illinois hospital, and was inspired to buy one and mimic the rig they were carrying:
Not sure of their carry load but they were carrying similar holsters and speedloader pouches. Knowing Illinois and its financial situation they’re probably still using these guns, but if you think about it, probably all they really need for that task.