Monolithic Bullet
Also: Solid Copper · Lead-Free
A one-piece copper or gilding-metal bullet with no separate lead core that penetrates deeply and runs long for its weight.
A monolithic bullet is machined or formed from a single piece of metal, typically copper or a gilding-metal alloy, with no separate jacket and lead core. Because copper is less dense than lead, a monolithic projectile is longer than a conventional bullet of the same weight, which has consequences for stability and seating. Many are designed with hollow noses that peel back into petals on impact while the solid shank drives straight ahead.
The chief appeal is deep, reliable penetration with very high weight retention, since there is no core to separate from a jacket the way a bonded bullet prevents by chemistry rather than construction. The extra length means shooters must confirm their twist rate is fast enough to stabilize these bullets, and monolithics are also the standard answer where lead-free hunting ammunition is required by regulation.