Semi-Jacketed Soft Point bullet. A lead core with a precisely engineered jacket results from its controlled expansion and high weight retention. For Solid Copper Technology, select Sellier & Bellot Exergy Centerfire Rifle Ammunition. This design brings in a new generation of ideas with precisely cut grooves within the all-copper construction. External ballistics are maximized by sealing the expansion cavity using aluminum, and this helps to optimize accuracy. When the Exergy bullet impacts the target, its concave tip (which includes a cannelure groove) and radius shape help with a controlled but fast expansion. The resulting ammo shows improvements over lead-core bullets, such as deeper penetration, a lack of fragments, and optimum weight retention. California Proposition 65 WARNING:This product can expose you to chemicals including lead, that are known to the State of California to cause cancer, and birth defects or other reproductive harm. For more information, go to www.P65Warnings.ca.gov