Coincidentally, I was reading this today.
"During World War Two Detective Specials were made for the US Government, often with the old original pre-1933 square butt. It's believed that these were simply pre-war Police Positive Special frames fitted with 2 inch barrels as a war-time expedient."
http://www.coltfever.com/Detective_Special.html
Phillip McGregor (OFC)
"I am neither a fire arms nor a ballistics expert, but I was a combat infantry officer in the Great War, and I absolutely know that the bullet from an infantry rifle has to be able to shoot through things." General Douglas MacArthur