s&w 500
Formally the Smith & Wesson Model 500, a very-large-frame double/single-action revolver designed around the .500 S&W Magnum cartridge. S&W advertised the Model 500 as "the world's most powerful handgun" (a title formerly claimed by the company's .44 Magnum Model 29 back in the 1970s) upon its release in 2003.
This tag implicates revolver (learn more).