This powerful-for-the-time cartridge was introduced in 1934 and was an almost immediate success. It is, in essence, a .38 Special case lengthened by 1/8th of an inch to prevent the possibility of firing the higher pressure round in chambers designed for .38 Special pressures.
Wikipedia credits Elmer Keith, Phil Sharpe, D.B. Wesson of Smith & Wesson, and Winchester, for the development of the cartridge. The 3rd Edition of Mike Bussard's Ammo Encyclopedia credits only Smith & Wesson.
Elmer Keith writes in his book Sixguns as follows: “Next we have the .357 magnum Smith & Wesson cartridge. I worked with Doug Wesson on this development and sent him the first Keith bullets used in developing the load. We also put 1000 rounds of 173 grain Keith solids backed by 11 grains No. 80 through a .38/44 Heavy duty S.&W. Revolver just to see if it would take them or blow up. They developed an average of 42,000 pounds and the gun held them with no danger.”
Phil Sharpe, in his book, Complete Guide to Handloading, wrote “The .357 Magnum cartridge was born in the mind of the author several years ago. On a hunting trip with Colonel D. B. Wesson, Vice-President of Smith & Wesson, a pair of heavy frame Outdoorsmen model revolvers were used with a large assortment of handloads developed and previously tested by the author. In the field they proved entirely practical, but Colonel Wesson was not content to attempt the development of a Magnum .38 special cartridge for ordinary revolvers, and set to work on a new gun planned in the field.”
However, a bit later in the same chapter, he wrote, “The author is not connected with any arms or ammunition maker and desires this fact clearly understood. He did not design the gun or the cartridge, although he cooperated and collaborated in a minor way.” Why he chose to distance himself from the project, I have no idea. Perhaps he was concerned about liability issues.
Both Keith and Sharpe mention Colonel Wesson and also Winchester in their writings on the .357 magnum, so it's a safe bet that all were involved.
For many years, starting around 1902, through essentially WWII, the chances of finding a police department armed with anything other than a revolver, either Colt or Smith & Wesson, chambered for the .38 Special cartridge, were about the same as finding a rooster with lips!
Police files are rife with hair raising details of police shootings which involved multiple hits on criminals and still having the perp wound or even worse kill the officer(s) involved. I personally witnessed such an event many years ago. The policeman involved was a friend of my family.
A few weeks before the incident, he had reluctantly accepted the job as Chief of Police of a small town. The town provided no equipment support and each LEO was required to provide his on handgun. The only one my friend owned was a WWII surplus 1911 auto in .45 ACP.
He caught all manners of flak about carrying such a cannon, so he traded it in on a new S&W Chief's Special. A few weeks later, while serving a warrant, he was involved in a shootout. He shot the perp several times, putting him on the ground, down but no where near out. The perp shot him from the ground and killed my friend instantly and he expired from his wounds later that evening.
Had the LEO still been armed with the 1911, I'm sure the outcome would have been far different.
Many police officers across the country upgraded their arms by adding a revolver chambered for the .357 magnum, often doing so at their own expense. While many Police Departments frowned on the practice, the officers could use either .38 Special or .357 magnum cartridges in the same revolver.
These days, most PDs around the country have armed their officers with semi-auto pistols. Quite a few switched to the 9mm Luger, but it is my sense that many have gone to larger calibers such as the .40 S&W, 10mm, or even the .45 ACP.
As I write these words, the US Army has announced that they are looking to replace the standard sidearm, the Beretta 9mm, with a larger, more powerful handgun/cartridge combination. I thought that they had learned that lesson in the Spanish-American conflict before the turn of the twentieth century.
I guess the old adage, the more things change, the more they stay the same, applies.