What characteristic is unique to hollow-point bullets?

Hollow-point bullets are specifically designed with a hollowed-out shape at the tip, which allows them to expand upon impact. This expansion increases their diameter as they travel through tissue, creating a larger wound channel and delivering more energy to the target. This feature is particularly advantageous for stopping threats quickly while also minimizing the risk of over-penetration, which can lead to unintended injuries.

Other characteristics associated with hollow-point bullets may include their construction from various materials, but their defining unique feature is the ability to enlarge during penetration. This is what differentiates them from other bullet types, like full metal jackets, which maintain their size and shape after impact. The other choices presented do not accurately reflect the defining attributes of hollow-point bullets.