The .22 Remington Jet (5.6x33mmR) is a .22 in (5.6mm) American centerfire revolver and rifle cartridge. The round is known in the US as .22 Jet, .22 Center Fire Magnum/.22 CFM or .22 Rem Jet.
Developed jointly by Remington and Smith & Wesson, it was to be used in the Model 53 revolver, which first appeared late in 1961. While it traced its origins to potent wildcats such as the .224 Harvey Kay-Chuk, which ultimately derive from the .22 Hornet, it was a bottlenecked cartridge based upon the .357 Magnum case necked down to a .22 caliber bullet, with an unusually long tapered shoulder.
By 1972, the Model 53 remained the only revolver chambered for it, while Marlin in 1972 was planning a lever rifle in .22 Jet. The .22 Jet was also a factory chambering for the Thompson/Center Contender and the design allowed for it to reach its full potential, having no cylinder gap and no case setback.
The .22 Jet was designed as a flat-shooting hunting round for handguns, and it is suitable for handgun hunting of varmints and medium game out to 100 yd (90 m). The 2460 ft/s (750 m/s) and 535 ft-lbf (725 J) claimed for factory test loads did not prove out in service weapons.