CCI Ammunition Subsonic, 22 LR, 40 Grain, Lead Round Nose, 100 Round Box 934CC The future of rimfire is here. CCI Clean-22 uses an exclusive polymer bullet coating to greatly reduce copper and lead fouling in the barrel-without leaving a residue. It also cuts lead buildup in suppressors 60 to 80 percent. Both the Sub-Sonic and High Velocity loads feature a 40-grain round nose lead bullet with geometry that's been optimized for accuracy. With dependable CCI priming and consistent propellant, Clean-22 provides flawless cycling through semi-automatics and all 22 LR firearms.