Broadly speaking, Smith & Wesson swing out cylinder (Hand Ejector) revolvers come in nine frame sizes. In order of increasing size, they are: M, I, Improved I, J, J Magnum, K, L, N, and X frame.
Perceiving a market for a more powerful pocket sized revolver, S&W introduced the J Magnum frame in 1995. It was created to accommodate the length of the .357 Magnum cartridge in a J frame revolver, having a longer cylinder and larger frame opening. This frame was first introduced as the Model 640-1 in 1995. Since then, other J frames, even .38 Specials, have been offered in this frame size. In 1996, the Model 60 (60-9) and 642 (642-1) were changed to the J Magnum sized frame.
The K frame was the original .38 caliber Hand Ejector frame introduced in 1899 as the Military & Police 1st Model. It served as the service revolver for the US Army in .38 Long Colt caliber until the adoption of the Colt 1911 autoloading pistol. The K frame was the most widely used and issued POlice revolver for nearly a century. The US Air Force continued to issue K frame revolvers to its Security POlice until almost the end of the 20th Century. It has been produced in a wide variety of calibers from .22 Long Rifle up to .357 Magnum but .38 S&W Special was the most popular.
Bill Jordan, of the US Border Patrol, convinced S&W to make the K frame size revolver in the .357 Magnum cartridge for POlice service. The .357 had only been produced in N frame revolvers until 1955. His original idea was to practice with .38 Special and only occasionally use .357s. As people started shooting .357 Magnums in quantity, they found that it was hard on a K frame. This led to the introduction of the L frame, which along with the other larger frame sizes will be covered in the next installment.
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Concealed Carry Skills and Drills http://concealedcarryskillsanddrills.com
Advanced Pistol Practice http://bit.ly/advancedpistolpractice
Shooting Your Black Rifle http://shootingyourblackrifle.com
Serious Mistakes Gunowners Make http://seriousgunownermistakes.com