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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.
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.
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.
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.
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.
Recently, there has been experiments done to make guided flechettes which can home in on targets. 
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.
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 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.
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.
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.
This weapon appears frequently in science fiction. For example it is featured in:
- Gene Wolfe's The Book of the Long Sun and The Book of the Short Sun
- Douglas Preston and Lincoln Child's Riptide
- Frank Herbert's Dune universe (variously referred to as needleguns, flechette guns, "Chandler" guns, and "maula" guns)
- Michael Moorcock's Jerry Cornelius stories (after which it is also the title of a Hawkwind song)
- Terry Brooks Genesis of Shannara series
- William Gibson's Neuromancer'
- The BattleTech universe
- Harry Harrison's Stainless Steel Rat stories
- Robert Heinlein's The Number of the Beast and other novels and stories
- Terry Pratchett's novel Strata
- Marvel Comics' Nick Fury, Agent of SHIELD
- Larry Niven's A Gift From Earth
- Gordon R. Dickson's Dorsai series
- Neal Stephenson's Snow Crash, in the form of a weapons system called Reason
- Dan Simmons's Hyperion and Endymion, as flechette rifles
- Also in Dan Simmons's Ilium and Olympos.
- The AM-280, from The War Against the Chtorr by David Gerrold.
- Lois McMaster Bujold's Vorkosigan Saga Universe.
- David Weber's Honor Harrington series depicts automatic weapons that fire flechettes in a manner similar to a coilgun.
- In Code Geass, Zero threatens Princess Euphemia with a ceramic needlegun.
- In The Disappearance of Haruhi Suzumiya, Kyon must use a needlegun to inject a program into Yuki Nagato after the collapse of the timespace continuum.
- In David Brin's The Practice Effect, protagonist Dennis Nuel uses a Needlegun.
- In Isaac Asimov's Lucky Starr series of novels, Starr's sidekick, Bigman, uses a needlegun.
- In the Hyperion fictional universe based upon Dan Simmons' novels, the "flechette rifle" or "flechette pistol" was loaded with "egg shaped" cartridges that, when fired, deployed into a cloud of several thousand hyper-velocity steel needles, in a manner similar to the discharge of a shotgun shell, though much more deadly and effective for longer range than a shotgun.
- In the Warhammer 40,000 universe, the Inquisition uses weapons called Needle Rifles or Needle Pistols that fire shards of crystallized venom that can be deadly when penetrating an unarmored or lightly armored target.
- In World War Z: An Oral History of the Zombie War, a post-apocalyptic horror-survival novel by Max Brooks, an interviewed soldier tells of "flechette-filled anti-infantry canister shots" for the M1A2 Abrams tank which are highly effective against zombies.
In video and computer games
- Messiah featured a weapon named "Pak Gun", or, simply, "The Pak", which fired small ice shards at a high rate; the shards had a tranquilizer-like effect, freezing the foe and causing good damage.
- A regular and Super-Nailgun were prominently featured as weapons in Quake. They were the equivalent of machine-gun style weapons that were able to fire rapidly by holding down the trigger. Quake II mission pack 1 featured a Flechette Rifle that functioned much like Quake's Nailgun. Quake III Revolution contains a nailgun, but it fires like a shotgun. Quake 4 features a rotary nailgun that functions much like the Super-Nailgun, but has a secondary homing function.
- Fallout 2 included a Needler pistol, speculated to once have been a scientific tool.
- Fallout 3 included a gun called the "Railway Rifle", which launches railway spikes via pneumatic pressure.
- Command & Conquer: Renegade features a Tiberium-based Flechette Gun.
- System Shock features a Flechette machine pistol.
- A needle gun is available for Regina in Dino Crisis 2. It is only used underwater, however.
- Marathon Infinity featured the KKV-7 submachine gun, which fired 4 mm flechettes from a 10 mm cartridge and was usable underwater.
- The Halo series features the Needler and Needle Rifle. Both fire long, sharp, pink glass shards that can "supercombine", resulting in an explosion if a critical amount of them have penetrated a soft target. The fully automatic Needler is appropriately known as Type-33 Guided Munitions Launcher. The Needle Rifle, which is introduced in Halo: Reach, is a longer, semi-automatic version that lacks the Needler's homing capabilities. The Spiker "carbine" (although it seems more similar to an SMG) used by the Brutes also fires needle-like projectiles, seemingly using a chemical propellant.
- In Turok: Evolution there is a Flechette gun which is the only weapon in the game to be able to fire underwater.
- Also, in Devil May Cry, the main character Dante has a weapon called a needle gun. It is the only weapon he can use underwater.
- In F.E.A.R. there is a rapid fire weapon known as the 10 mm HV Penetrator that fires nails that can be used to stick enemies to walls.
- Team Fortress 2's Medic class is armed with a Syringe Gun which fires what appear to be extremely sharp used medical syringes, and the Scout class was originally going to have a nail gun as its primary weapon.
- The Engineer class in Star Wars Battlefront 2 can earn an upgraded shotgun called a "Flechette shotgun" and can only be used by a player controlled character.
- In Thing Thing 4 there is a Flechette Rifle available in the final levels. It features minimal recoil but is difficult to find ammo for.
- In Half-Life 2: Episode 2, enemy types called "Hunters" fire flechettes that can either disintegrate the enemy or detonate for explosive damage.
- In Buck Rogers: Countdown to Doomsday, your team could equip a high rate of fire weapon called a "needler" which used needle-like projectiles.
- Aliens versus Predator and its sequel Aliens vs. Predator 2 both feature the Predators' speargun, which fires a powerful metal needle-like projectile, called a spear.
- In Battlefield 3 you can use "Flechette" shotgun rounds.
- In Call of Duty: Black Ops 2, there is a weapon, known as the Titus-6, that fires explosive flechettes as well as standard buckshot. It is only used in Campaign.
- In Freelancer, you can purchase a "small arms" item for selling/trading to other space stations or planets, and can contain shoulder fired needle rifles.
- In Team Fortress series (except Team Fortress 2).
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:
- BattleTech, as needler pistols and rifles
- Star Frontiers, as needler pistols and rifles
- Gamma World, as needler pistols and rifles
- Traveller, in the form of gauss-pistols and gauss-rifles firing 4mm darts.
- Shadowrun, as flechette pistols and rifles; these weapons use chemically-propelled flechette ammunition cartridges.
- Renegade Legion, as rifles, carbines and pistols. In this setting, needler weapons all share a common ammo type; a block of solid plastic that is shredded at tremendous velocities.
- Sprague, Richard E. and Cutler, Robert The Umbrella System: Prelude to an Assaination Gallery Magazine June 1978
- Bond: A Spy's Report on 007's Next Movie Thunderball Esquire June 1965