Special Purpose Individual Weapon
The Special Purpose Individual Weapon Program ( SPIW for short ) was a long-running US Army project to develop a rifle that was supposed to fire arrow-shaped projectiles - so-called flechets . Other and expanded concepts were also pursued as part of the SPIW project. The SPIW continued in the Future Rifle Project and culminated in the Advanced Combat Rifle Program. In the end, none of the projects turned out to be promising enough to replace the established M16 assault rifle or its derivatives.
SALVO project
The idea of the flechet weapon was concretized in the SALVO project . As part of the SALVO , it was defined that a weapon with high cadence was much more effective than weapons with larger calibers such as those developed in the 1950s. Different concepts were pursued that followed different principles: On the one hand, research was carried out on weapons that could fire two projectiles with one charge, and on the other hand, experiments were carried out with several barrels, for example by Springfield Armory or Olin / Winchester.
Even before the SALVO tests, Irwin Barr of AAI Corporation had developed single and multiple "arrow" bullet cartridges. The US Navy was interested in the concept and supported development through the Office of Naval Research , which resulted in a 32-arrow shotgun . The US Army later also participated in the financing and so AAI was invited to SALVO. The SALVO tests found that the light arrows could penetrate a standard steel helmet at 500 yards (460 m), but the spread of the arrows was too great for meaningful use.
The advancement came by adapting a Winchester Model 70 rifle with the XM110 5.6 × 53 mm cartridge that could fire a single arrow. The result was a weapon with slightly less accuracy than the 7.62 × 51mm cartridge but with the same penetration and an extremely flat trajectory that could be fired up to 400 yards (370 m) without cant. Due to the low weight and the fact that the weapon had almost no recoil compared to the common 5.56 × 45 mm caliber, a weapon with extremely high cadence seemed possible.
When the SALVO project was started in 1951, it was assumed that a large number of projectiles fired would increase the probability of being hit, since in World War II an infantryman with a rifle fired several thousand rounds for one hit. Since SALVO mainly carried out studies on weapons and ammunition and no direct development was initiated, the development was partly uncoordinated. It was found, however, that high-speed projectiles with a smaller caliber had the same or greater lethality than 7.62 mm and at the same time had a lower weight. It was also researched that fully automatic firing did not increase the probability of hits and that flechets were too imprecise.
Since the army was only researching fully automatic weapons up to this point, Barr suggested a multi-barreled weapon and several prototypes were built to test the concept. In the 1961 test it was found that the cadence was up to 2300 rounds per minute due to the low weight of the arrow and that from a gun loaded with 60 rounds and weighing only 1.6 kilograms. According to this information, the army was very interested in the weapon, but SALVO was discontinued in favor of the introduction of the AR-15 , the forerunner of the M16.
Project NIBLICK
In the meantime, the US Army's Operations Research Office is working on the NIBLICK project with the aim of developing a modern grenade launcher . The focus here was on the use of cartridges similar to shotguns that Flechets should fire, in combination with an underflow grenade launcher. This led to the actual SPIW . The final specification led to weapons that would fire arrows from the barrel and grenades from the grenade launcher mounted under the barrel. The weight should be less than 4.5 kg with three grenades and 60 arrow projectiles.
Four companies responded to the tender: AAI, Springfield Armory, Winchester, and Harrington & Richardson (H&R). AAI continued to work with the original XM110 cartridge, while Springfield and Winchester used a new XM144 cartridge in caliber 5.6 × 44 mm.
The H&R design was the most advanced and used an arrow with its own cassette design (XM144), in which the arrow was placed between three sabot (sabot) in a triangular plastic cartridge . After firing, the sabot parts fell off and the arrow flew on. In contrast to the weight of the arrows, the weapon was very heavy at 11 kg and so it was eliminated from the competition.
Winchester used a concept of a "soft recoil charger" in which the energy of the recoil should be absorbed by a spring. The idea was to fire three shots before the spring was completely compressed, so that only a slight recoil should be felt until the end of the burst. This should drastically increase the accuracy in the burst. The system never came to functional maturity and was dropped, but the grenade launcher part was further developed.
The Springfield design was very interesting in that it placed two 30-round magazines back-to-back on a Bullpup weapon. However, the massive magazine grenade launcher lifted the weight up to 6.4 kg and a weight reduction seemed unlikely.
Oddly enough, the AAI's design was the most technologically advanced. The flechette part was a little heavy, but reached a rate of 2400 rounds per minute. The grenade launcher was a simple single-shot version as the semi-automatic version was not completed for testing.
The conclusion of the test was that none of the weapons was suitable for developing a weapon system on it. The AAI Flechet part and the Winchester grenade launcher were interesting for general development. The result of the general examination of the Flechet concept was sobering: While the weapons kept their promises of extremely high rates of fire and excellent penetration, the cartridges were extremely expensive to produce and the arrows could be easily deflected in flight even by heavy rain. In addition, the muzzle bang and the fire were very noticeable, which would have made it easier to explain the shooter.
A second round of testing took place with the Springfield model and the Winchester grenade launcher with a disposable magazine and a changed layout for the arrow bullet magazines. The AAI design has now been fitted with their semi-automatic grenade launcher and a new plastic shaft / visor system. The updated versions did not prove to be very reliable, nor did they meet the weight specifications. In 1966 the SPIW project was stopped and the M16 was taken over.
AAI continued development at a low level and eventually managed to dramatically improve the reliability of their XM19. Now another problem was revealed: The heat build-up in the chamber was so great that a cook-off could be triggered. Due to changes in the army command structure and the adoption of the M16 in general troop service, interest in the SPIW faded and the project was discontinued. Ironically, the original and simple AAI grenade launcher became a huge success: in 1968 it was selected as the M203 grenade launcher in combination with the M16.
Future Rifle Program
In 1969 the US Army started the Future Rifle Program . After Springfield was closed in 1968, the US Army invited AAI to compete against General Electric's "Dual Cycle Rifle" (DCR), a derivative of the Springfield SALVO design. Other companies - for example the French VFIW assault rifle - also made other designs with arrow projectiles or micro-projectiles, but the results reflected the findings of the SALVO tests of the 1950s. The program came under fire from the United States Congress as a waste of money and they were forced to scale back the project. When the final tests began in 1974, the AAI rifle was unable to deliver more than six uninterrupted bursts of fire. The Future Rifle Program was discontinued without success.
Close Assault Weapon System (CAWS)
In the early 1980s, the concept of the automatic shotgun was revived, which, according to the SALVO project, should have an increased hit rate. As part of the Close Assault Weapon System, a number of designs were submitted that showed good reliability. Heckler & Koch developed the weapon for this, while the ammunition came from Winchester. The weapon was tested by the US military, but the project was canceled because the concept of a heavy weapon with dubious effectiveness at distances over 100 m was not considered sustainable.
Advanced Combat Rifle (ACR)
The concept of flechet ammunition was last picked up during the Advanced Combat Rifle (ACR) studies in the late 1980s. Several designs were tried out, from the relatively simple Colt ACR to the more interesting Flechet designs like the Steyr ACR . Although the basic problem of ammunition with an arrow was eventually solved, none of the weapons tried brought the improvement that the US Army had requested. This means the end for the ACR project.
See also
literature
- Charles R. Shrader; United States. Dept. of the Army. "History of operations research in the United States Army". Government Printing Office ISBN 978-0-16-087337-9
Individual evidence
- ↑ The 5.56 X 45mm: 1957-1962. (No longer available online.) The Gun Zone, archived from the original on December 26, 2014 ; accessed on May 26, 2014 (English).
- ^ SLA Marshall: Men against Fire: The Problem of Combat Command in Future War . Morrow, New York 1966, pp. 50-60.