

Barrel lengths were offered from 26 inches to 32 inches. Model 21 grades at this time were chambered in 12, 16 and 20 gauge.410 bore was offered in Custom Grade only and is extremely rare only exceeded by the rare (8 known) 28 gauge guns produced.

The Model 21 has a considerable collectors following as it is regarded as almost a custom-made shotgun. The Model 21 was Winchester's effort to make a quality side by side shotgun to rival those of high-end makers such as Parker and Fox financial troubles plagued the gun's development until the Western Cartridge Company purchased Winchester Repeating Arms in 1931.

Like all quality double guns, production is time-consuming due to the laborious process of joining the barrels to produce an identical convergence of shot. The Winchester Model 21 action is of a typical breech loading shotgun, commonly called a break or hinge action. New Winchester Model 21 production continues under license to Connecticut Shotgun Manufacturing Company. Winchester Repeating Arms Company ceased the main production line of this shotgun in 1960 and the Model 21 was sourced to the Winchester Custom Shop until the gun's retirement in 1991. The shotgun's initial production run from 1931 through 1960 yielded approximately 30,000 guns. The Winchester Model 21 is a deluxe side by side shotgun.
