The very-low-drag bullet (VLD) is primarily a small arms ballistics development of the 1980s–1990s, driven by shooters' desire for bullets that will give a higher degree of accuracy and kinetic efficiency, especially at extended ranges. To achieve this, the projectile must minimize air resistance in flight. Demand has been greatest from military snipers and long range target shooters, including F-class and benchrest competitors, but hunters have also benefited. Most very-low-drag bullets are used in rifles.
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Bullets with a lower drag coefficient decelerate less rapidly. A low drag coefficient flattens the projectile's trajectory and also markedly decreases the lateral drift caused by crosswinds. The higher impact velocity of bullets with low drag coefficients means they retain more kinetic energy.
Development
The development of very-low-drag bullets has focused on the following main factors:
The resulting projectile should be streamlined for easier passage through the air. Consistency in bullet production, allied to consistency in the assembly of cartridges (quality control) should give excellent shot-to-shot consistency.
The principles of bullet design and flight are classically set out in F.W. Mann's The Bullet's Flight From Powder to Target: Ballistics of Small Arms.
Modern design
The possibility to machine mono-metal bullets (coreless bullets made of one single metal (alloy)) offers bullet designers the freedom to design slender, aerodynamically efficient shapes that cannot be produced with more traditional bullet production methods.
Mono-metal very-low-drag bullets are normally machined from solid bars of highly-machinable metals or alloys using CNC lathes. Common materials include UNS C36000 Free-Cutting Brass, lead-free brass, oxygen-free copper and other highly machinable alloys of copper, nickel, and tellurium.
Producing accurate bullets this way is not easy. To guarantee the bullets' consistency and accuracy, professional quality control during and after production is needed. Mono-metal solid bullets are more expensive than traditional jacketed Hollow Point Boat Tail very-low-drag bullets.