Sten Mk IV
Royal Small Arms Factory Enfield · Submachine Gun · Prototype · 1943
Also known as: Sten Mk IV-A, Sten Mk IV-B, Sten Mark IV
Overview
The Sten Mk IV was an experimental compact variant developed in 1943 for British airborne troops. It featured a drastically shortened barrel, a conical flash hider, a rear pistol grip and a folding buttstock to make it small enough to be jumped with already assembled. Two main prototype variants were trialled (Mk IV-A with a side-folding stock, and another with an underfolding stock) but neither entered production, as the existing Mk II proved adequate and the design was deemed unnecessary by 1944.
Specifications
| Weight (empty) | 3500 g (123.5 oz) |
| Overall Length | 686 mm (27.01") |
| Folded Length | 470 mm (18.50") |
| Barrel Length | 95 mm (3.74") |
| Action Type | Blowback |
| Firing Mechanism | Open Bolt |
| Trigger Type | Single Stage |
| Magazine Capacity | 32 rounds |
| Magazine Type | Detachable Box |
| Muzzle Velocity | 305 m/s (1001 fps) |
| Muzzle Energy | 347 J (256 ft·lbf) |
| Effective Range | 50 m (55 yd) |
| Maximum Range | 100 m (109 yd) |
| Rate of Fire | 575 rpm |
| Barrel Rifling | Right Hand |
| Number of Grooves | 6 |
| Frame Material | 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
- Feed systems: Detachable Box Magazine
- Safety mechanisms: Bolt Locking Notch
- Features: Folding Buttstock, Rear Pistol Grip, Conical Flash Hider, Shortened Barrel, Compact Design, Airborne Optimized
Variants
- Sten Mk IV Type A — Rounded Pistol Grip
- Sten Mk IV Type B — Underfolding Stock
Base model
Production
Estimated total produced: 8 · Production years: 1943-1944
Only a handful of prototypes built; never entered serial production. Surviving examples are extremely rare and held primarily by museums such as the Pattern Room collection
Origin
Country of origin: United Kingdom
Discontinued: 1944
Notes
Sometimes referred to as the 'Pistol-sized Sten' due to its compact dimensions. The conical flash hider was added to control the violent muzzle flash produced by the very short barrel. Specifications vary considerably between the prototype variants and many figures are estimates from surviving examples.
Background
British airborne troops jumping with the Sten Mk II had to detach the stock from the receiver to make it compact enough for the parachute jump, then reassemble it under fire on the drop zone. The Mk IV was specifically designed to spare paratroopers those crucial seconds, but the war ended before the design could be perfected.