Hard core bullet
A hard core bullet is a projectile with high penetrating power, which is mostly used because of its armor-piercing effect . The projectiles, which are usually referred to as Armor Piercing Composite Rigid or APCR for short , belong to armor-piercing ammunition .
Structure and effect
In the case of a hard core bullet, the inner part consists of a particularly hard, and preferably also heavy and heat-resistant material, such as tungsten alloys or tungsten carbide , while the outer part consists of a softer alloy, for example aluminum in a tombac jacket .
If the projectile were made entirely of the hard material of the core, this would lead to problems with the internal ballistics , since a projectile for tubular weapons with rifled barrels has a larger diameter than the barrel itself and is literally pressed through it, thereby reducing its spin and thus maintaining flight stability ( external ballistics ). But this only works if the outer material of the bullet is softer than that of the barrel. When it hits a solid target ( target ballistics ), the hard core penetrates the target surface, while the softer jacket breaks down due to the impact shock.
Hard-core projectiles from handguns were used, for example, in World War I to combat the lightly armored protection of machine-gun positions. Something similar to hard core ammunition is sabot ammunition, which , however, is mostly fired from smooth-barreled cannons and in which the projectile loses its "coat", i.e. the sabot or sabot, as soon as it leaves the barrel.
Example of hard core ammunition
An example of hard core bullets is the SmK (H) rifle cartridge ("pointed bullet with core (hard metal)") in caliber 7.92 × 57 mm (also called 8 × 57 IS). At a muzzle velocity of around 750 meters per second (m / s) at a distance of 100 meters and an impact angle of 60 degrees, it penetrates steel armor almost 15 mm thick. In contrast, the SmK bullet contained only a hardened steel core, which had a much lower penetration rate.
Legal
The possession of hard core ammunition is prohibited in Germany according to the Weapons Act (Appendix 2, Section 1, Item 1.5.4).