The lower flat portion of the barrel (visible only when the shotgun is broken open or disassembled).
The Cooey Model 840 serial number range spans from 1948 to 1982, with over 260,000 units produced during this period. The serial numbers are typically found on the receiver, barrel, or stock, and are usually a combination of letters and numbers. The serial number range can be broken down into several sections:
Any authentic Model 840 stamped with "Cobourg, Ontario" was made before the 1979 shutdown.
If your rifle has a serial number, it was almost certainly made , when Winchester (which had purchased Cooey in 1961) began applying serial numbers for export or post-1968 U.S. market compliance. Cooey Model 840 Serial Number Lookup
Originally, Cooey produced the single-shot break action as the Model 84 starting around 1948.
An upgraded version of the 840, produced around the same time. Winchester Model 37A: Followed the 370.
Cooey Model 840 Serial Number Lookup: A Complete Identification Guide The lower flat portion of the barrel (visible
If your gun has a serial number on the barrel but also says "Made in Canada" with an importer's stamp (e.g., "O.F. Mossberg & Sons"), it was an American-export model from the 1960s. In this case, the serial number is purely for US GCA 1968 compliance and offers no date.
Post-1968 models often feature a serial number starting with a letter.
You might find a number on the barrel lug or the inside of the forearm. These are generally assembly numbers used to keep parts together during manufacturing, not unique serial numbers that can be looked up. The serial number range can be broken down
If your gun looks exactly like a Cooey Model 840 but has a completely different name stamped on it, you likely own a "hardware gun." During the mid-20th century, Cooey and Winchester manufactured thousands of unbranded or alternative-branded shotguns for major department stores and hardware chains. Common store-brand aliases for the Cooey Model 840 include:
While a definitive digital database for a Cooey Model 840 serial number lookup doesn't exist, the gun itself tells its own story. By evaluating the presence of a serial number, analyzing the manufacturer's roll marks, and checking the wood styling, you can confidently narrow your shotgun's birthdate down to a highly accurate window. The Cooey Model 840 remains an enduring symbol of rugged North American craftsmanship—a simple, honest firearm built to last a lifetime. Share public link
Remove the barrel from the stock (the Model 840 has a simple takedown screw on the forend). On the underside of the barrel, near the chamber, you may find small stamped letters or numbers. These are often "fitting codes" or inspection stamps (e.g., a circle with "WP" for Winchester proof), not true serial numbers.
If your serial number lookup yields vague results, you can narrow down the production era using design characteristics: The Winchester Transition (1961–1979)