Jacketed Pistol Bullets
Lead: Simple cast, extruded, swaged, or otherwise fabricated lead slugs are the simplest form of bullets. At speeds of greater than 300 m/s (1000 ft/s) (common in most handguns), lead is deposited in rifled bores at an ever-increasing rate. Alloying the lead with a small percentage of tin and/or antimony serves to reduce this effect, but grows less effective as velocities are increased. A cup made of harder metal, such as copper, placed at the base of the bullet and called a gas check, is often used to decrease lead deposits by protecting the rear of the bullet against melting when fired at higher pressures, but this too does not solve the problem at higher velocities.
Jacketed Lead: Bullets intended for even higher-velocity applications generally have a lead core that is jacketed or plated with cupronickel, copper alloys, or steel; a thin layer of harder metal protects the softer lead core when the bullet is passing through the barrel and during flight, which allows delivering the bullet intact to the target. There, the heavy lead core delivers its kinetic energy to the target. Full metal jacket bullets or Ball bullet have the front and sides of the bullet completely encased in the harder metal jacket. Some bullet jackets do not extend to the front of the bullet to aid in expansion and increase lethality. These are called soft points or hollow point bullets. Steel bullets are often plated with copper or other metals for additional corrosion resistance during long periods of storage. Synthetic jacket materials such as nylon and Teflon have been used with limited success.
Armor Piercing: Jacketed designs where the core material is a very hard, high-density metal such as tungsten, tungsten carbide, depleted uranium, or steel. A pointed tip is often used, but a flat tip on the penetrator portion is generally more effective.