The U.S. Office of Strategic Services (OSS) used flechettes in mini crossbows and handgun spigot launchers. Spigot launchers were a device that went on the muzzle of the M1911A1 pistol, rather like a rifle grenade launcher. A rod acted as the firing pin extension to transfer the blow to the primer in the device. The cartridge was self-contained, as ignition drove a piston which did not leave the cartridge case, thereby containing the expanding powder gasses so that the cartridge produced little noise. The piston drove a big flechette ahead of it, which shot from the launcher as a projectile dragging the cartridge case with it.

The big flechette had enormous killing power due to its size, which was important when only one shot can be made. The large flechette was more deadly than a small caliber handgun but produced similar or audible less report. This made the spigot launcher a single-shot weapon of great value for covert assassinations where the sound of a gun firing could alert the enemy forces and hinder escape.

This system was used in Vietnam with Smith & Wesson .44 Magnum revolvers bored out to accept this sort of cartridge except that in these, the piston drove a conventional bullet out ahead of it. In these, the case stayed in the gun. These were well appreciated by the “tunnel rats” who had to fire in tightly confined spaces where the noise of a normal gun was greatly magnified to a permanently deafening level. A silent weapon was a necessity if you wanted to avoid deafness. The U.S. Navy also had a revolver firing one large flechette on this principle for underwater use. The Russians copied this design to work with smaller cartridges in a compact automatic pistol also adapted the design for use in an underwater gun.

The need for an improved cannister round for tank guns led to research in flechettes loaded in artillery shells as an alternative. This research bore much fruit during the Vietnam War when flechettes were used in 12-gauge shotguns, 40 mm grenade launchers, 2.75-inch and 5-inch aircraft rockets, 81 mm riverine mortars, 90 mm and 106 mm recoilless rifles, 105 mm howitzers, 120 mm cannon, and in 90 mm, 105 mm, and 152 mm tank guns.

Anti-war protestors, championing the communist side in the Vietnam War, attacked the use of flechettes vehemently as these munitions were devastating to the communist forces attacking American soldiers. The political pressure they brought to bear resulted in a decline in the fielding of flechette systems, which left American forces more vulnerable to communist human wave assaults.

Today, Israel makes a copy of the U.S. 105 mm tank flechette round and both Russia and China reportedly maintaining large inventories of flechette ammunition for their major caliber artillery.

Current U.S. fielded flechette munitions include the 70 mm Hydra rocket (a modernized version of the 2.75-inch rocket), 84 mm Carl Gustov recoilless rifle munitions, and classified defense systems. Both the 70 mm Hydra rocket and the 84 mm Carl Gustov recoilless rifle flechette loads have been used in the Global War on Terror that began in 2001.

FLECHETTE SHOTGUN SHELLS

The use of flechettes in shotgun shells is the most common small arms employment of flechettes and the application of most interest to civilians. Credit for being the first to apply this concept to small arms goes to Irwin R. Barr of Aircraft Armament Co. in the early 1950’s. Originally, the idea was for one flechette per round and this led to the Army’s SPIW program. The first shotgun shells were loaded in 1953. These 32 flechettes-per-round loads were of a smaller size than those of today.

During the Vietnam War, flechette-loaded shotgun shells made kills out to 100 yards, proving their worth as a military weapon. Whirlpool Corporation had done development work on them, also loading many shells. Federal Ammunition made them, loading 25 flechettes per round while Western Cartridge Company’s load held 20 flechettes per round. Both of these rounds had their flechettes in a plastic cup buffered with granulated white polyurethane powder to maintain bore alignment. There was a metal disk at the rear of the cup the prevented the wad from being driven through the sharp tail fins of the flechettes. The tips of the flechettes were exposed and were visible at the mouth of the cartridge case These rounds would ruin a choke if fired through one, and they were only used in cylinder bore riot guns.

SPECIFICATIONS

Sometimes at gun shows, I have seen shotgun shells loaded with surplus artillery flechettes. Typically, some are loaded forwards and some backwards. Do not fire these in anything. They will tear up the inside of a shotgun barrel, as the hard steel of the flechettes will plow furrows in the bore and destroy any choke that gets in their way.

Properly loaded flechette shotgun shells are available from Sabot Designs LLC. The current loads are safe to use in any shotgun and will not hurt even a full choke, as the bore and choke are protected from the hard steel flechettes by a patented sabot that prevents any metal-on-metal contact. This was the invention of the firm’s oner, John Flannigan, and enables them to be used in any shotgun, not just cylinder bored riot guns.

Considered by many to be the greatest expert in flechette design and manufacture, much of Flannigan’s work remains classified, but what we can divulge is impressive. He made experimental tantalum flechettes for the Naval Surface Warfare Center’s Cargo Round. He designed and manufactured tungsten flechettes for the NSWC EMRG electro-magnetic rail gun sub-munition. His collaboration with General Dynamics Ordnance and Tactical Systems on the development and testing of the “High Density Packing” (HDP) cannister for the M1 Abrams tank resulted in his patent for the HDP Cannister round. Lockheed-Martin engaged him as a consultant for the fin design of the flechette projectiles for the Hydra-7 mine clearing system. The Marines Corps had him develop a flechette round for shooting down drones. That’s about all that we are free to talk about though.

FLECHETTES COMPARED TO BUCKSHOT

Comparing flechettes to the old standard, buckshot, reveals the strengths and weaknesses of both. Buckshot depends on its size, weight, and momentum to produce casualties. Of all projectiles, buckshot’s round ball deflects the least when hitting foliage and twigs. For this reason, it was often favored in jungle encounters.

Flechettes have 211% more projectiles per shell than buckshot which greatly increases the chance of a hit at longer ranges. They have 19 projectiles compared to just nine in the military buckshot load. Flechettes are a near perfect aerodynamic shape, whereas the round ball is the least aerodynamic. Furthermore, lead balls tend to deform when fired so they are not even perfectly round anymore. At longer ranges this becomes more of a factor. Additionally, flechette loads weigh about half as much as an equivalent buckshot load, so combatants can carry more ammo into the fight.

The stopping power of flechettes is a result of their velocity, penetration, and energy. Each flechette has the same energy signature as a 9 mm Parabellum round. It will shoot through a car door and produce a casualty on the other side, or it will go through over 20 inches of ballistic gelatin. Its energy is transmitted to a casualty by creating a supersonic cavitation wound channel. It will yaw off course as it penetrates, creating a wound channel approximately 800% larger than the flechette. This averages about .58 caliber for each flechette. Flechettes may also bend or break, creating secondary wound channels. They also typically shatter bones on contact.

ENGAGEMENT RANGES

* This being the longest range that a single flechette will produce a casualty.

CIVILIAN USE

12-gauge shotgun flechette loads are extremely useful to civilians. I’ve heard of a person taking out the heart and lungs of a wild hog at seven yards that was chasing and about to overtake his friend. Flechettes will penetrate the thick skull of an enraged bull or a 1000-pound hog when buckshot may fail. Flechettes have proven effective on deer, turkey, wild hog, and bear and are earning a devoted following among hunters. People depending on a shotgun for home defense are looking to flechette rounds for increased effectiveness.

Ever since the American Derringer Co. first invented the pistol chambering both the .45 Colt and the 2.5-inch .410 shotgun shell in 1980, there have been more companies making pistols that chamber these rounds interchangeably. Sabot designs makes a 2.5-inch .410 flechette load with seven flechettes for these.

Standard flechette rounds may not function reliably in automatic shotguns. Rounds that will reliably function a semi-auto are available under special order from Sabot Designs LLC.

Like birdshot, slugs, and buckshot, the flechette shotgun load has taken its place among the standard loads available for shotguns today.

By Steve Fleischman

Since the beginning of war, throwing objects has been the most popular form of combat. Whether it be rocks or 2000 pound projectiles, hitting your opponent with something has been the goal.

Grenades through history have evolved from light and throw bombs to primitive Civil War potatoes with tail fins, to all forms of Pineapple, egg, and can-shaped objects. All had one thing in common, a good throwing arm was needed.

A variety of rifle-launched objects also evolved with mixed results on accuracy and effect.

After the Korean War there was a need for a new delivery system for antipersonnel munitions, with greater effectiveness and range. The criteria for this new system was lightweight, range out to 400 yards, effective fragmentation, low recoil, and low cost.

Development and manufacture of this weapon system was a multi-faceted effort, of government and private industry. The Vietnam War put additional pressure on the development, which resulted in significant refinement-production techniques, improved quality, and substantial cost reduction.

The shoulder-fired M79 launcher was the first weapon developed to deliver the first production round, the M406 HE. The M203 launcher replaced and paralleled the M79 as an additional weapon system. The M203 was mounted on the M16A1 rifle.

Grenade ammunition up to now was known as HI-LO pressure type with about the same power as a 45 long Colt. A new longer-range offensive type grenade was now being developed that was to be fired from a multitude of weapons being designed. There were a variety of fully automatic belt-fed systems that were developed, such as the M75, XM129, and MK19. All ammunition for these weapons is known as HI pressure type.

Grenade ammunition is basically divided into several categories. First, HI-LO and HI- pressure as defined above. Next we will define as to type, HE, Practice, Pyrotechnic, smoke, riot, shot and “specials”. These specials are just representative samples of a multitude of special purpose cartridges produced experimentally, sometimes field tested and most times just abandoned.

HI-LO Pressure

HE M406, Round notched sphere bomblet, spin and setback armed point detonating fuse.

HEDP M433, cylindrical steel body, shaped charge, light armor defeating. Fuse is a point detonating with a spitback charge to initate the shaped charge.

HEAP. This He anti-personnel was developed by FN of Belgium using a ball matrix fragmentation and a combo point detonating /time fuse.

HE AIRBURST M397. Special fusing and projectile design produced a new round with the old “bouncing betty” concept. An HE round striking the ground loses half or more of its effectiveness when it detonates. This round rebounds its bomblet to two meters above the ground before it detonates.

PROOF XM387E2. Black heavy projectile, for proofing M79/203.

PRACTICE. Multitude of plastic and metal case and projectile combinations with orange dye markers. Basic issue is the M781, white plastic case, blue plastic nose.

PRACTICE M407A1. This round is an HE simulator, two kinds, and one totally inert with dummy fuse, and the other with a smoke spotting charge.

SHOT. Two styles of XM576, E1 and E2. See reference picture for different shot charge and sabot design. There was even a silenced version developed by AAI.

FLECHETTE. A multitude of different loads and sizes were experimented with.

SMOKE. For all kinds of spotting and signaling. There is ground smoke-M713, red, M714 violet, M716 yellow, and M715 green. Parachute smoke- XM659 red, XM669 violet, XM660 yellow, and XM658 green. Streamer smoke- XM696 yellow, XM697 green, XM699 red, XM698 orange, XM701 violet, and XM700 brown. Canopy smoke- XM682 red, XM681 violet, XM680 white, XM676 yellow, and XM679 green. There is an experimental floating smoke marker that uses a balloon inflated by the burning smoke compound. This system allows it to float on water and or mud and burn for 70 seconds.

PYROTECHNIC. All kinds of signaling cartridges were designed. The main two types were the parachute star XM583 white, XM661 green, XM662 red, and XM695 orange. And the Cluster star XM585 white, Xm663 green, and XM664 red.

RIOT. Many CS gas rounds were developed for non-lethal removal of undesirables and also a variety of plastic and rubber baton rounds.

DBCATA. This silenced round was developed to replace the M203 barrel system. The round was its own barrel, which clipped on to a firing device, which looked very much like the receiver of a 203. The case was rifled and the projectile was pre-engraved. A steel foil “balloon” was folded up and sealed around the propelling charge. When fired the propelling gasses expand the balloon and push out the projectile, with enough force to impart sufficient spin and setback to arm the fuse. The balloon captures all the gases and makes the round silent. DBCATA stands for Disposable-Barrel-Cartridge-Area-Target-Ammunition.

ROCKET ASSISTED. Many types were developed and tested for increased range. Primers and igniters were part of the rocket and came through the back of the case.

ANTENNA CARTRIDGE GR103. This round contained a coil of wire and when fired above the jungle canopy deployed the wire as an antenna. Developed for Navy Seals for burst radio transmission.

MULTI PELLET CARTRIDGE as the military called it. This round was loaded with 18 -22 lr cartridges. A large rifle primer propelled a disc with 18 firing pins which fired all rounds at once. There was no rifling so the bullets tumbled soon after leaving the weapon. This was good or bad depending on what was trying to be achieved. The original military version had a safety wire on its reloadable one. There was also a die-cast throwaway one.

GRAPPLING HOOK PROJECTOR XM688. This round was developed for the Rangers to propel climbing devices higher and farther than they could throw.

M42 MINE PROJECTING. Little is known about this round, except that it propels 2 shaped charge mines of the same type as deployed in other types of ordnance.

FLECHETTE BIOLOGICAL TRANSMITTING. This round has 4 very large flechettes and it is alleged to be some kind of delivery method for what ever you can think of.

HI PRESSURE ROUNDS FOR MK19-XM175.

TARGET PRACTICE M385. Solid Aluminum projectile.

TARGET PRACTICE M918. HE projectile filled with Aluminum slug, inexpensive fuse and spotting charge.

PROOF XM385E3. Heavy Aluminum projectile for proofing weapons.

DUMMY XM922. Gold color, for training.

HEDP M430. Hi velocity shaped charge, for light armored targets up to 2 inches thick.

HE M384. First adopted HE round for the hi velocity series

HE AIRBURST. This experimental round using the M384 body incorporates a self-contained proximity fuse that sends out its own signal and detonates itself at a predetermined distance from the target.