XM19 SPIW
AAI Corporation (Textron Systems) · Assault Rifle · Prototype · 1964
Also known as: AAI SPIW, Special Purpose Individual Weapon
Overview
The XM19 SPIW is an experimental American flechette-firing assault rifle developed by AAI Corporation under the U.S. Army's Special Purpose Individual Weapon (SPIW) program during the 1960s and early 1970s. It fired a fin-stabilized 5.6mm flechette dart from a smoothbore barrel at extremely high velocity, and offered a very high cyclic rate of fire intended to improve hit probability in burst fire. Like other SPIW entrants, the XM19 was paired with an integral multi-shot grenade launcher. Despite years of development, persistent problems with flechette accuracy, dispersion, and cost meant the program never produced a service weapon, and the XM19 remained a prototype.
Specifications
| Weight (empty) | 2880 g (101.6 oz) |
| Overall Length | 940 mm (37.01") |
| Barrel Length | 559 mm (22.01") |
| Action Type | Gas Operated |
| Firing Mechanism | Hammer Fired |
| Trigger Type | Single Stage |
| Magazine Capacity | 60 rounds |
| Magazine Type | Detachable Box |
| Muzzle Velocity | 1402 m/s (4600 fps) |
| Muzzle Energy | 648 J (478 ft·lbf) |
| Effective Range | 400 m (437 yd) |
| Rate of Fire | 2200 rpm |
| Barrel Rifling | Smoothbore |
| Frame Material | Steel |
| Barrel Material | Steel |
| Stock Material | Polymer |
| Finish | Parkerized |
Calibers
- 5.6mm Flechette · primary — also known as XM110, XM144, XM645, 5.6mm SPIW flechette
Features
- Firing modes: Semi Automatic, Burst 3, Full Automatic
- Feed systems: Detachable Box Magazine
- Safety mechanisms: Manual Safety
- Features: Flechette Ammunition, Smoothbore Barrel, Integral Grenade Launcher, Burst Fire, High Cyclic Rate
Service history
Operators
- United States Army · as XM19
Production
Production years: 1964-1974
Only experimental prototypes built; never entered series production
Origin
Country of origin: United States
Designer: AAI Corporation
Discontinued: 1974
Notes
Part of the long-running SPIW program that sought to replace the M16 with a flechette weapon. The flechette ammunition went through several iterations (XM110, XM144, XM645). The program's failure to deliver a practical flechette rifle later fed into the ACR (Advanced Combat Rifle) effort of the 1980s.
Background
The SPIW program embodied the U.S. Army's 1960s belief that the future of small arms lay in salvo and flechette fire rather than conventional bullets. The tiny tungsten or steel darts flew flat and fast, but proved difficult to manufacture cheaply and to stabilize accurately, and the rifles became heavy and complex once a grenade launcher was bolted on.