Remington has been building rimfire ammunition for generations, and Thunderbolt is the round that made shooters believe in the name. As Remington's best-selling rimfire load of all time, it pairs a 40-grain lead round nose bullet with a high-velocity, supersonic charge for reliable function and dependable accuracy... box after box, range day after range day. Load up for target shooting, training new shooters, and plinking with a round you can count on.