Sjögren Inertia Shotgun
Haandvaabenværkstederne Kjøbenhavn · Shotgun · Discontinued · 1908
Also known as: Sjögren Inertial Shotgun, Sjögren Patent Autoloading Shotgun
Overview
The Sjögren Inertia Shotgun is a 12-gauge inertia-operated semi-automatic shotgun designed by Swedish inventor Carl Axel Theodor Sjögren. Reaching the market around 1908, it predated the Browning Auto-5 as the first commercially offered self-loading shotgun. It used a fixed barrel and a fully locked breechblock, with the rearward inertia of the recoiling shell re-cocking the firing pin and unlocking the bolt once chamber pressure dropped to a safe level. This inertia-driven principle was later revived by Benelli and remains widely used in modern shotguns.
Specifications
| Weight (empty) | 3400 g (119.9 oz) |
| Overall Length | 1180 mm (46.46") |
| Barrel Length | 700 mm (27.56") |
| Action Type | Inertia Operated |
| Firing Mechanism | Hammer Fired |
| Trigger Type | Single Action |
| Magazine Capacity | 4 rounds |
| Magazine Type | Tubular |
| Muzzle Velocity | 400 m/s (1312 fps) |
| Effective Range | 40 m (44 yd) |
| Barrel Rifling | Smoothbore |
| Frame Material | Steel |
| Slide Material | Steel |
| Barrel Material | Steel |
| Stock Material | Wood |
| Finish | Blued |
Calibers
- 12 Gauge · primary — also known as 12ga, 12 Bore
Features
- Firing modes: Semi Automatic
- Feed systems: Tubular Magazine
- Safety mechanisms: Manual Safety
- Features: Fixed Barrel, Locked Breech, Inertia Operated, Tubular Magazine, Choke Bored Barrel
Service history
Operators
- Danish Army
Conflicts
- World War I (1914-1918)
- World War II (1939-1945)
Production
Estimated total produced: 5,500 · Production years: 1908-1909
Approximately 5,000 to 5,500 made across Swedish and Danish production; serial numbers ran from 1001 to 6000, with an extra 500 cylinder-bore barrels produced.
Origin
Country of origin: Denmark
Designer: Carl Axel Theodor Sjögren
Discontinued: 1909
Notes
Roughly 5,000 to 5,500 examples were produced between 1908 and 1909, manufactured in Sweden by AB Svenska Vapen- och Ammunitionsfabriken and in Denmark by Haandvaabenværkstederne in Copenhagen. Standard barrels were 700 mm with 3/4 choke; an additional batch of 600 mm cylinder-bore barrels was also made. It saw very limited military and paramilitary use through World War I, the interwar period, and World War II.
Background
The Sjögren beat John Browning's Auto-5 to market as the world's first commercially available self-loading shotgun, and its inertia-driven action anticipated the system Benelli would make famous decades later.