Remington .22 Thunderbolt Rimfire Ammunition is a .22 round designed for a long rifle and offers a lead round nose as well as high velocity. These bullets design have a weight of 40 grains.The high velocity offered by the .22 Thunderbolt ammunition is no exaggeration, as it can reach 1,255 feet per second with a muzzle energy of 140 foot-pounds. This particular ammo usually comes in packages of 500 rounds, providing more than enough for your next shoot, whether it's competition, plinking, or hunting.