BTHP meaning in General ?

A hollow-point bullet is a type of expanding bullet used for controlled penetration, where over-penetration could cause collateral damage (such as aboard an aircraft). In target shooting, they are used for greater accuracy due to the larger meplat. Hollow point bullets are more accurate and predictable compared to pointed bullets which, despite having a higher ballistic coefficient (BC), are more sensitive to bullet harmonic characteristics and wind deflection.

Plastic-tipped bullets are a type of (rifle) bullet meant to confer the aerodynamic advantage of the spitzer bullet (for example, see very-low-drag bullet) and the stopping power of hollow point bullets.

This bullet expands on impact causing a more lethal hit without penetrating further than necessary.