When was a Winchester cooey model 840 serial?

The Winchester Cooey Model 840 is a .22 caliber rifle that was produced by the Cooey Firearms Company in Canada, which was later acquired by Winchester. The production of the Model 840 began in the early 1960s and continued until the late 1970s. Serial numbers on these rifles can help determine the production year, with the first digits generally indicating the year of manufacture. For precise dating, it's best to consult a reference guide or database specific to Cooey firearms.