Lead-Free Bullet
A bullet built with no lead core, usually solid copper, used where lead is restricted or where deep, controlled penetration is wanted.
A lead-free bullet replaces the traditional lead core with a non-toxic material, most often a solid copper or copper alloy projectile machined as a single piece. Because copper is less dense than lead, a lead-free design of a given weight runs longer than its conventional counterpart, which shifts how the bullet balances and stabilizes.
That extra length is why a monolithic bullet often needs a faster twist rate to keep it stable in flight. Shooters choose lead-free designs both to satisfy regulations in areas that restrict lead and for terminal performance, since a one-piece copper bullet tends to hold together and drive deep rather than shedding fragments.