Tag Archives: Standard Catalog of Smith & Wesson

S&W Revolver Frame Sizes (part I)

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First in an ongoing series. This series owes much to the Standard Catalog of Smith & Wesson. The book is a valuable resource for anyone interested in S&W products and especially the revolvers.

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. The factory uses a separate system for lettering stainless steel frames but they are seldom used outside the factory so will not be used here. The most commonly encountered frame sizes today are the J and J Magnum. In the 20th Century, the K frame in various permutations became the dominant POlice revolver in the USA and many people can recognize it on sight. Prior to 1957, their revolvers were named. In 1957, the firm switched to a numbering system that is still in use today.

In the named models, evolutions of a particular model were referred to as 2nd Model, 3rd Model, etc. or 1st Change, 2nd Change, etc. Numbered models have the model number stamped on the frame inside the yoke. In the numbered models, a dash and numeral following the model number is part of the model designation, e.g., 38-2.

The M frame, the original Ladysmith, is a truly tiny revolver that was in production only until 1921. It was made in .22 Long (not Long Rifle) caliber and weighed 9.5 ounces. There is a rumor that it was discontinued because it was a favorite weapon of Ladies of the evening but this is unlikely. An enterprising manufacturer could probably reproduce this revolver with a dual firing pin of the sort used in the original Henry rimfire rifle and enjoy brisk sales.

The I frame was the original S&W swing out frame sized for the .32 caliber cartridge. The I frame was the first S&W revolver with a swing out cylinder; it was introduced in 1896 and became the first Hand Ejector purchased by a US POlice department, Jersey City, New Jersey. They were referred to as ‘Hand Ejectors’ because previous S&W revolvers were top breaks and ejected the cases automatically. Swing out cylinder revolvers require the user to manually eject the cases by pushing on the ejector rod, hence the name Hand Ejector.

Improved I frames have a very slightly larger frame opening than the I frame. The most noticeable feature of the Improved I frame was an engineering change from using a leaf type mainspring to a coil mainspring. The Improved I can be easily distinguished from the I because the Improved I lacks a screw (strain screw) at the bottom of the grip frame. Both the I and Improved I frame openings are too small for the .38 Special cartridge.

S&W developed the J frame in order to allow the use of the .38 Special in a revolver significantly smaller than the K frame, which had been in service for many years. The J frame continued the use of the coil mainspring of the Improved I frame but has an increased frame opening of 1.645 inches compared to the 1.515 frame opening of the Improved I frame.

The larger frame sizes will be covered in the next installment.

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