Which statement best describes the general difference between FMJ and Jacketed Hollow Point ammunition and typical law enforcement usage?

• A. FMJ expands on impact; JHP feeds reliably.
• B. FMJ feeds reliably and penetrates; JHP expands on impact for controlled penetration and stopping; LE often uses JHP to reduce over-penetration.
• C. FMJ is designed for hunting; JHP is designed for practice.
• D. FMJ and JHP are interchangeable in all scenarios.

Answer: (B)

Full Metal Jacket rounds have a hard metal jacket around a softer core, which helps the bullet feed reliably in many firearms and preserves its shape as it penetrates. Because the jacket prevents the bullet from expanding, FMJ tends to penetrate deeply with little change in diameter, which means less disruption to the target and a higher chance of exiting the body or passing through walls. Jacketed Hollow Point rounds, on the other hand, are designed with a hollow space in the tip that causes the bullet to mushroom and expand upon impact. This expansion increases the diameter inside the target, creating a larger wound channel and transferring more energy into the target while reducing penetration depth. That combination—controlled penetration with a greater stopping effect and reduced risk of over-penetration—drives typical law enforcement use of JHP for duty weapons. FMJ is more common for training and practice because of its reliable feeding and predictable penetration, but less ideal from a safety standpoint in urban settings.