There WAS a smoothbore version of the Winchester 67, made to fire 22 LR SHOT (only) The smoothbore 22s are properly called shotguns, since they are not rifled. Shot rounds CAN be fired out of a rifled bore, but the spin imparted by the rifling will make the shot pattern resemble a doughnut, and give an effective range of about 25 FEET. The 22 LR SHOT cartridge has a tint load of VERy fine shot. Orginally a metallic cartridge with a crimped end, they are now made with a hollow plastic "bullet" filled with fine shot- usually #12 (see also lead dust) Mossberg (and others) made 22 smoothbores, and there was even one .20 cal rimfire used for INDOOR skeet shooting.