AAI SPIW
AAI Corporation (Textron Systems) · Assault Rifle · Prototype · 1964
Also known as: AAI Special Purpose Individual Weapon, AAI SPIW flechette rifle
Overview
The AAI SPIW is an experimental American assault rifle developed by AAI Corporation for the U.S. Army's Special Purpose Individual Weapon program in the early to mid-1960s. It fired the XM110 5.6mm flechette cartridge, a sub-caliber finned steel dart roughly 40mm long and 1.8mm thick, through a gas-operated smoothbore action capable of a very high cyclic rate in burst. The weapon paired its flechette rifle with an integral three-shot 40mm grenade launcher, fed from a tubular magazine behind the barrel, to give the individual soldier both flat-shooting penetration and area effect. It was never adopted and its development line continued into the XM19 Serial Flechette Rifle.
Specifications
| Weight (empty) | 5000 g (176.4 oz) |
| Weight (loaded) | 5900 g (208.1 oz) |
| Overall Length | 1016 mm (40.00") |
| Barrel Length | 457 mm (17.99") |
| Action Type | Gas Operated |
| Firing Mechanism | Hammer Fired |
| Trigger Type | Single Action |
| Magazine Capacity | 60 rounds |
| Magazine Type | Drum |
| Muzzle Velocity | 1402 m/s (4600 fps) |
| Muzzle Energy | 648 J (478 ft·lbf) |
| Effective Range | 300 m (328 yd) |
| Rate of Fire | 2400 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 Drum Magazine
- Safety mechanisms: Manual Safety
- Features: Integral Grenade Launcher, Flechette Ammunition, Smoothbore Barrel, Three Round Burst, Drum Magazine
Service history
Operators
- United States Army · as SPIW (trials only)
Production
Production years: 1964-1968
Small number of prototypes built for U.S. Army SPIW trials; not mass-produced
Origin
Country of origin: United States
Designer: AAI Corporation
Discontinued: 1968
Notes
Prototype only; never standardized. The flechette used a distinctive piston-primer ignition system. Burst-mode cyclic rate reached roughly 2,300-2,400 rpm, with a lower 600-700 rpm full-auto rate. Weight_empty estimated from the 5.9 kg loaded figure.
Background
The SPIW program grew out of Project SALVO, which concluded that multiple small flechette hits could equal a single rifle bullet. AAI's flechette darts flew at over 1,400 m/s, but accuracy, dispersion, and the troublesome integral grenade launcher kept the concept out of service, with development eventually narrowing to the XM19.