Since 1922 Winchester Super X ammunition has provided exceptional quality and outstanding performance for all types of hunters and shooters who rely on it’s time-proven dependability backed by legendary excellence.These rimfire cartridges are loaded with No. 12 shot. Shot cartridges may not function in semi-automatics or feed in some repeating firearms.FeaturesCrimped shell loaded with No. 12 pelletsProven AccuracySure FunctioningExceptional QualityOutstanding PerformanceTime-Proven Dependability