Needlegun

APS amphibious rifle

This article is about the modern firearm that fires small fin-stabilized metal darts. For the early rifle known as the "needle gun" see "Needle gun."

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

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 cannonball.

Flechettes again came into mass use in World War I, when they were dropped from airplanes.

A June 1978 issue of Gallery Magazine quotes L. Fletcher Prouty observing a test of flechette weapons in 1960 and the testimony of William E. Colby in the Church Committee on September 16 to 18, 1975 describing flechette weapons. Charles A. Senseney testified that he was a project engineer of the M-1 dart launcher that was described as resembling a M1911 pistol with a sight mount at the top.

Senseney claimed the M-1 was designed for the US Army Special Forces to be used in the Vietnam war but never got there due to not being able to get into the US Army's logistics system in time. Flechette ammunition encased in a sabot was available for the M-16, shotguns, and other weapons for use in Vietnam.

A June 1965 Esquire magazine story on the making of the then upcoming James Bond film Thunderball featured drawings of dart firing pistols that were not used in the completed film.

At the same time, several makes of underwater firearms fired a steel bolt just over 4 inches long (but without fins).

More recently, several flechette weapon systems have been developed, but none appear to be in mass production.

Flechette-firing rifles

The Special Purpose Individual Weapon was a long-running United States Army program to develop, in part, a workable XM-216 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.

Advantages

Theoretically, the advantages of a needlegun over conventional projectile firearms are in its compact size, high rate of fire, and extreme muzzle velocity. A needlegun leverages the principles of kinetic energy and conservation of momentum, resulting in a low-recoil delivery system capable of inflicting significant damage to a soft target. Recoil is generated by the ejecta, which in a chemical firearm includes not only the projectile itself but the hot expanding exhaust gasses, ejected empty catridge and any moving parts. Since the needle is the only moving part of a needlegun (as in a coilgun or railgun), there is inherently little recoil. Although it has extreme velocity, the needle possesses little mass, providing even less potential for recoil. A high rate of fire allows a massive number of projectiles to be fired in a very short period of time, before any perceivable recoil could begin to affect the user's accuracy.

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 directly 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 have mass of 147 grains, but a typical Flechette and Sabot for the same 7.62X51 weapon would have mass of only 38 grains, for a substantial reduction in recoil and a very large increase in muzzle velocity.

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 a coilgun would not work with projectiles made purely of these materials, although a railgun would.

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. The low mass and large, irregular shape of the pieces of the sabot give them poor aerodynamic qualities and thus danger zone is very short.

See also

• AO-27 rifle
• APS underwater rifle
• Flechette
• SCIMTR
• SPIW
• Steyr ACR