The Taurus Model 66 was introduced in 1978 as a medium-frame, six-shot double-action revolver chambered in .357 Magnum and .38 Special. As noted in the History of the Taurus Model 66, the firearm was "introduced in 1978, is the Brazilian equivalent of Smith & Wesson's Model 19/66 Combat."Early versions of the gun closely resembled Smith & Wesson revolvers. This came from shared engineering resources and design similarities during the 1970s and 1980s. However, the internal parts are different. Taurus uses a coil mainspring and a transfer bar safety instead of the flat leaf spring and hammer block safety found in older Smith & Wesson models. [1] (https://www.youtube.com/shorts/GIGNKMKbb-o), [2] (https://www.youtube.com/watch?v=oHSV2z_Hd-8), [3] (https://www.youtube.com/watch?v=m8yRhY07rzI)