Needlegun

There are other articles with similar names; see Needle gun (disambiguation)

A needlegun, also known as a needler, flechette gun or fletcher, is a firearm that fires small, sometimes fin-stabilized, metal darts.

Contents

History

The first projectiles in early gun systems dating from the 14th century were typically hand wrought iron flechettes wrapped in a leather sabot. However, due to the expense and trouble of making these darts in a pre-industrial society, they were soon replaced with the less accurate stone cannon ball.

Flechettes again came into mass use in World War I, when they were dropped from airplanes. More recently, several flechette weapon systems have been developed, but none appear to be in mass production.

Flechette ammunition encased in a sabot is available for the M-16, shotguns, and other weapons.

There are some makes of underwater firearms which fire a steel bolt just over 4 inches long (but without fins).

The US Army established a Special Purpose Individual Weapon program which produced several successful automatic flechette rifles, but none had enough advantages over the M16 to switch.

Advantages

Theoretically, the advantages of a needlegun over other projectile weapons are its compact size, high rate of fire, and ultra-high muzzle velocity. A needlegun takes advantage of the principles of kinetic energy and conservation of momentum, allowing a low-recoil delivery system to inflict significant damage to a target. Recoil is governed by momentum, which is the product of velocity and mass. By conservation of momentum, the change in momentum of the gun must equal the change in momentum of the projectile. The needle projectile has a very small mass, so its large change in velocity does not result in much recoil (change in velocity of the gun itself) since the gun has a mass much larger than the mass of the needle. Damage inflicted is related to the kinetic energy imparted by the projectile on the target, which is 1/2 the projectile's mass multiplied by its velocity squared. Since the needle has a very high velocity and a negligible mass, recoil is minimized at little cost to the kinetic energy of the projectile and its damage potential. The high rate of fire allows the user to fire many needles quickly with a minimal loss of accuracy due to recoil effects, giving the needlegun supposedly large damage potential and precision in combat.

Some hypothetical needlegun designs are solid state, meaning that the delivery system has no moving parts other than the projectile itself. For instance, see coilgun and railgun.

Disadvantages

Terminal Ballistics

In real-world firearms, terminal ballistics is often at least as important as aerodynamic efficiency. Rather than inflicting their full kinetic energy on a target, needle projectiles tend to pass smoothly through the target with little damage, similar to needles for textiles or medical usage.

Low-Recoil Operation

A powder-based propulsion system requires a barrel seal, which needles have a hard time providing at high rates of fire without damaging the barrels. Sabot systems result in smaller decreases in recoil (which is proportional to momentum) compared to a full-size projectile, they allow an increase in projectile velocity per unit of barrel length. A typical full bore projectile might Mass 147 grains, but a typical Flechette and Sabot for the same 7.62X51 weapon would Mass only 38 grains, for a substantial reduction in recoil and a very large increase in MV.

Projectile Materials

Lead, used almost universally in firearms for its high density and softness which allows it to pass through rifled gun barrels at high velocity, is unsuitable for a needle for this same reason - it cannot hold its shape without a stronger jacket. Steel jacketed lead core Flechettes are used in some sporting ammunition. Other dense, strong metals like tungsten and depleted uranium have not had the same historical evaluation as projectile materials because of their comparative rarity - and electromagnetic propulsion systems would not work with projectiles made purely of these materials.

Collateral damage

Flechette projectiles do not deflect off typical surfaces as easily as regular bullets due to the longer distribution of mass and reduce the danger to bystanders. In addition to this many flechette systems use self-discarding sabots that exit the barrel at dangerous speeds which can potentially harm allies or bystanders close by the muzzle. Their low mass and large, irregular shape give them poor aerodynamic qualities and very short danger zones.

Flechette-firing rifles

The Special Purpose Individual Weapon was a long-running United States Army program to develop, in part, a workable flechette-based "rifle", though other concepts were also involved. The concepts continued to be tested under the Future Rifle Program and again in the 1980s and 1990s under the Advanced Combat Rifle program, but neither program resulted in a system useful enough to warrant replacing the current M16.

In fiction

This weapon appears frequently in science fiction. For example it is featured in:

In video and computer games

In role-playing games

Drawing their inspiration largely from similarly themed literature, science-fiction role-playing games frequently include needle-guns in some form. For example:

See also