Section 6: BALLISTIC ATTACK HARDENING
Introduction. This section provides a summary of the available
information on the ballistic resistance of commercial construction,
structural barriers, doors, and glazing materials against small arms and
military threats, i.e., the ballistic attack. In a ballistic attack, the
aggressor fires various small arms such as pistols, rifles, submachine guns,
and shotguns from a distance determined by the range of the firearm and
accessibility to the asset. A ballistic attack requires line-of-sight access
to the asset being attacked, at as close a range as practicable. Firearms,
which may be civilian or military, are described in terms of ballistic
standards developed for testing the resistance of building components to the
weapons' effects. These standards generally specify weapons, ammunition,
muzzle velocity of the round, and number of rounds fired at the target.
Ballistic Threat Characteristics. The ballistic threat posed by a
bullet depends on its caliber, type, shape and weight, impact velocity, angle
of impact, muzzle energy, multiple versus single impact, and target range.
The most probable threat is from pistol, rifle, submachine gun, or machine
gun fire. Coverage of the ballistic threat in this handbook is limited to
bullets or projectiles fired from small arms; the penetration mechanics of
these bullets or projectiles, and the architectural application of ballistic-
resistant materials or armor. The term "ballistic-resistant" refers to
protection against complete penetration, passage of projectile fragments, or
spallation (fragmentation) of the protective material to the degree that
injury would be caused to an asset or a person standing directly behind the
Caliber. The caliber of a bullet refers to its diameter and is
expressed either in decimals of an inch or in millimeters. Typical examples
include the 0.303-caliber high-power rifle and 7.62-mm NATO rifles.
Bullets vary in their characteristics.
Armor-Piercing (AP). A bullet having a hardened metal core, a soft
metal envelope, and a bullet jacket. When the AP bullet strikes armor, the
envelope and jacket are stopped, but the armor-piercing core continues
forward to penetrate the armor. The AP bullet is characterized by high
accuracy in flight and high velocity.
A non-armor-piercing bullet having a lead or mild steel
Other Characteristics. The different bullet designs are spire
point, round nose, flat point, full metal jacket, boat-tail hollow-point,
short jacket, cast bullet, and wadcutter. Ballistic performance of a
material is sensitive to a projectile's shape and construction, e.g., whether
or not the bullet is jacketed, the length, thickness, and hardness of the
jacketed material, the presence of a hollow nose, a cavity and hollow base,
and the hardness of the lead.