The Smith & Wesson model 22 series revolvers is a refined, commercial version of the M1917 revolver issued during World War I.
It is a large frame double-action revolver chambered in .45 ACP using half or full moon clips. It may also use .45 auto-rim as they were designed for revolvers chambered in .45 ACP or .45 GAP using the half or full moon clips. Built around S&W's large N frame it was originally sold as the Model 1950 and is normally fitted with a 5½" barrel with no under lug and fixed combat sights. Target models are the model 25 and 26.
The model 22 was re-introduced as the 2nd limited production Thunder Ranch revolver in 2007. This gun features a 4" match barrel with under lug, fixed sights, coccobolo grips, and an internal lock. The popularity of this revolver led S&W to continue its production in its classic line as the 22-4. It is quite an accurate revolver and has a smoother trigger pull than the original, most likely due to improvements in production. A limited production of bright nickel-plated, NON-Thunder Ranch models were made. Exact numbers of production are not known to this author; but, they are some of the most collectible models of the 22-4 available. Only select firearm dealers were considered to be allowed to sell this particular model.