Lead-Free Shot Pellets
Steel shotshell pellets
Concern over the potential effects of the ingestion of lead shot by waterfowl led to the adoption of lead-free shot for hunting. Soft steel was the first substitute pellet material. Pellets start as molten mild steel that is ejected at high speed and pressure into a water spray booth. The steel hardens into spheres and ovoids; the same shape-sorting process used for lead shot separates the best pellets for waterfowl ammunition. As field experience with the new pellets increased, it became obvious to hunters that the lighter, faster steel pellets were much different in performance than lead pellets. The transition to the use of steel shot also required the development of special wads to prevent damage to gun barrels.
Tungsten, nickel, bismuth, and mixtures of these have increased pellet density closer to that of lead. Due to competition, most manufacturers do not release details of how they make their nontoxic products. Some of the two-component nontoxic pellets are sintered. Powdered metals in the correct proportion are pressed and heated in molds, fusing them into solid pellets.