The determination of the density of bullet components is a quick and simple test that can, in most instances, distinguish between armor-piercing and conventional ammunition. Ordinarily, most bullets associated with a criminal investigation are either lead or lead core with a copper jacket. Since these bullets are usually lead alloys rather than pure lead, their densities vary somewhat from that of pure lead. Armor-piercing projectiles, on the other hand, fall into a distinct range of densities below those of the lead alloy/jacketed projectiles. These data were obtained through the use of simple density measurements by means of Archimedes Principle. A zone of density demarcation distinguishes conventional projectiles from armor-piercing projectiles. Armor-piercing projectiles may be harder than conventional projectiles, but most armor-piercing projectiles will be less dense than lead. In the ammunition examined in this study, only one exception was found. The one exception, the 7.62 NATO SLAP with a tungsten alloy penetrator, has a density significantly greater than conventional ammunition. The authors conclude that density measurements are a good indicator, but cannot be a sole indication, of whether the ammunition is composed of materials used in the manufacture of armor-piercing projectiles. It may be necessary in some instances to cross- section the projectile and examine the entire configuration, including the core, to identify definitively armor-piercing handgun ammunition. 4 tables and 10 references