HK33A3
Heckler & Koch · Assault Rifle · Discontinued · 1968
Also known as: HK33A3, HK33
Overview
The HK33A3 is the retractable-stock configuration of the Heckler & Koch HK33 assault rifle, chambered in 5.56x45mm NATO. Mechanically identical to the fixed-stock HK33A2, it substitutes a sliding telescoping metal buttstock for the solid polymer one, letting the rifle collapse to 735mm for carry in vehicles, by airborne troops, or for special operations use while still extending to a full 940mm shooting length. It retains the HK33's roller-delayed blowback action, fluted chamber, stamped-steel receiver, 390mm cold-hammer-forged barrel and 25-round magazine. The compact, configurable form factor made the A3 a favourite for mechanized and special-purpose units among the HK33's many export operators in Asia, the Middle East and Latin America.
Specifications
| Weight (empty) | 4000 g (141.1 oz) |
| Overall Length | 940 mm (37.01") |
| Folded Length | 735 mm (28.94") |
| Barrel Length | 390 mm (15.35") |
| Action Type | Roller Delayed Blowback |
| Firing Mechanism | Hammer Fired |
| Trigger Type | Single Stage |
| Magazine Capacity | 25 rounds |
| Magazine Type | Detachable Box |
| Muzzle Velocity | 950 m/s (3117 fps) |
| Muzzle Energy | 1805 J (1331 ft·lbf) |
| Effective Range | 400 m (437 yd) |
| Rate of Fire | 750 rpm |
| Barrel Rifling | Right Hand |
| Rifling Twist | 178 mm (7.01") |
| Number of Grooves | 6 |
| Frame Material | Stamped Steel |
| Barrel Material | Steel |
| Stock Material | Steel |
| Finish | Matte Black |
Calibers
- 5.56x45mm NATO · primary · 5.56mm NATO — also known as 5.56x45mm, 5.56 NATO, .223 Remington
Features
- Firing modes: Semi Automatic, Full Automatic
- Feed systems: Detachable Box Magazine
- Safety mechanisms: Manual Safety Selector, Fire Selector
- Features: Roller Delayed Blowback, Fluted Chamber, Retractable Stock, Select Fire, Cold Hammer Forged Barrel, Drum Type Rear Sight, Bayonet Lug
Base model
Service history
Operators
- Royal Thai Armed Forces
- Malaysian Armed Forces
- Chilean Armed Forces
Conflicts
- South Thailand Insurgency (2004-present)
- Kurdish-Turkish Conflict (1978-present)
Production
Production years: 1968-2001 (Germany), 1981-present (Turkey)
Produced in Germany by HK and license-built in Turkey (M79), Thailand and Malaysia.
Origin
Country of origin: Germany
Designer: Tilo Moller
Discontinued: 2001
Notes
The A3 suffix denotes the retractable metal stock; the HK33A2 is the otherwise identical fixed-stock version. Overall length is 940mm extended and 735mm collapsed. The retractable stock adds roughly 350g over the fixed-stock A2. Standard magazines hold 25 rounds, with 30- and 40-round options available.
Background
The HK33A3's sliding metal stock collapses the rifle to barely longer than a submachine gun, which is exactly why special operations and airborne troops favored it over the bulkier fixed-stock A2.