Editing Terminal ballistics (section)

=====Frangible=====
The last category of expanding bullets is [[Frangible bullet|frangible bullets]]. These are designed to break upon impact, which results in a huge increase in surface area. The most common of these bullets are made of small diameter lead pellets, placed in a thin copper shell, and held in place by an epoxy or similar binding agent. On impact, the epoxy shatters, and the copper shell opens up, the individual lead balls then spread out in a wide pattern, and due to their low mass-to-surface area ratio, stop very quickly. Similar bullets are made out of [[Sintering|sintered]] metals, which turn to powder upon impact. These bullets are usually restricted to pistol cartridges and rifle cartridges intended for use at very short ranges, as the nonhomogeneous cores tend to cause inaccuracies that, while acceptable at short ranges, are not acceptable for the long ranges at which some rifles are used.

By far the most common use of frangible ammunition is for training by shooting steel targets at close ranges, while one may be at risk of being injured by fragments of standard solid lead bullets at close ranges when shooting steel, the powder that frangible bullets disintegrate into upon impact poses a very low risk to the shooter. This becomes irrelevant when shooting at longer ranges because it is unlikely that fragments created by the impact of any type of bullet on a steel target will travel more than 50-100yds, in these long-range cases it is of more value to use bullets that fly identically to those to be used in real situations than to mitigate the possible risks of bullet fragments and ricochets so frangible bullets are typically not used. One interesting use of the sintered metal rounds is in shotguns in hostage rescue situations; the sintered metal round is used at near-contact range to shoot the lock mechanism out of doors. The resulting metal powder will immediately disperse after knocking out the door lock and cause little or no damage to the occupants of the room. Frangible rounds are also used by armed security agents on aircraft. The concern is not depressurization (a bullet hole will not depressurize an airliner), but over-penetration and damage to vital electrical or hydraulic lines, or injury to an innocent bystander by a bullet that travels through a target's body completely instead of stopping in the body.