Interdynamic MP-9
Interdynamic AB · Submachine Gun · Discontinued · 1983
Also known as: MP9, Interdynamic MP-9 SMG
Overview
The Interdynamic MP-9 is a Swedish-American blowback-operated, closed-bolt submachine gun chambered in 9x19mm Parabellum. Designed by Swedish engineer George Kellgren (Goran Kjellgren) and built by Interdynamic AB of Stockholm, with US production through Interdynamic USA of Miami, it was conceived as an inexpensive, fast-firing weapon drawing on the layout of the Carl Gustav m/45. Fed from detachable box magazines of up to 32 rounds and fitted with a collapsible wire stock, the select-fire MP-9 cycled at roughly 1,000 rounds per minute. Interdynamic failed to attract any military buyers, and only a few dozen registered select-fire examples were ever produced. The design was instead reworked for the US civilian market as the open-bolt semi-automatic KG-9 pistol, which went on to spawn the Intratec KG-99 and the notorious TEC-9.
Specifications
| Weight (empty) | 1700 g (60.0 oz) |
| Overall Length | 541 mm (21.30") |
| Folded Length | 328 mm (12.91") |
| Barrel Length | 173 mm (6.81") |
| Action Type | Blowback |
| Firing Mechanism | Closed Bolt |
| Trigger Type | Single Action |
| Magazine Capacity | 32 rounds |
| Magazine Type | Detachable Box |
| Muzzle Velocity | 396 m/s (1299 fps) |
| Muzzle Energy | 584 J (431 ft·lbf) |
| Effective Range | 55 m (60 yd) |
| Maximum Range | 150 m (164 yd) |
| Rate of Fire | 1000 rpm |
| Barrel Rifling | Right Hand |
| Rifling Twist | 254 mm (10.00") |
| Number of Grooves | 6 |
| Frame Material | Stamped Steel |
| Barrel Material | Steel |
| Stock Material | Steel |
| Finish | Phosphate |
Calibers
- 9x19mm Parabellum · primary · 9mm NATO — also known as 9mm Luger, 9mm NATO, 9x19mm
Features
- Firing modes: Full Automatic, Semi Automatic
- Feed systems: Detachable Box Magazine
- Safety mechanisms: Manual Safety
- Features: Select Fire, Collapsible Stock, Barrel Shroud, Stamped Steel Receiver, Extended Magazine Compatible, Threaded Barrel
Variants
- Interdynamic KG-9 — Semi Automatic Derivative
Production
Estimated total produced: 50 · Production years: 1983-1984
Fewer than 50 registered select-fire MP-9s were produced, perhaps as few as 24 in the select-fire-with-collapsible-stock configuration. All US-registered examples were transferable pre-1986 machine guns. The far more common open-bolt semi-automatic KG-9 derivative was produced in much larger numbers (around 2,500) for the civilian market.
Origin
Country of origin: Sweden
Designer: George Kellgren
Discontinued: 1984
Notes
The MP-9 is the original select-fire submachine gun from which the civilian KG-9 pistol (and later the TEC-9) was derived by removing the stock and converting to semi-automatic-only fire. Reported figures vary between sources; weight is cited around 1.7 kg, barrel length around 173 mm, and overall length 328 mm with the stock collapsed and 541 mm extended. Fewer than 50 select-fire MP-9s were built, with as few as roughly 24 in the full select-fire-with-stock configuration, making genuine examples extremely rare. The overall_length_mm field records the stock-extended length; the stock-collapsed length is approximately 328 mm.
Background
The MP-9 is the obscure Swedish ancestor of one of America's most notorious firearms. Designer George Kellgren could not interest any government in his cheap submachine gun, so partner Carlos Garcia took it to the US market as the semi-automatic KG-9. After the ATF reclassified the open-bolt KG-9 as a machine gun in 1982, the design was reworked into the closed-bolt KG-99 and then the Intratec TEC-9, a fixture of 1990s crime imagery. Kellgren went on to found Grendel and later Kel-Tec, designing far more respected weapons such as the SUB-2000 and KSG.