In terms of expansion and penetration, which statement is correct?

• A. Hollow-points expand to increase stopping power and reduce overpenetration; FMJ tends to penetrate more with less expansion.
• B. Hollow-points penetrate more with less expansion; FMJ expands more.
• C. Hollow-points always overpenetrate; FMJ never penetrates.
• D. Hollow-points are illegal for civilian use; FMJ is safe.

Answer: (A)

Expansion and penetration move in opposite directions for these bullet types. Hollow-points are designed to expand upon impact, increasing their diameter. That expansion uses more of the bullet’s energy inside the target, causing a larger wound channel and quick energy transfer, which tends to stop the threat sooner while reducing the chance that the bullet zips through the target and continues on. In contrast, full metal jacket bullets resist deformation, so they don’t expand much and tend to penetrate deeper with less energy being dumped into the target. This combination—expansion that boosts stopping power and limits penetration, versus deeper penetration with little expansion—is why the statement matches how these bullets perform in practice.