Heckler & Koch HK433
Heckler & Koch · Assault Rifle · In Production · 2017
Also known as: HK433, HK 433, HK433 MARS
Overview
The Heckler & Koch HK433 is a modular assault rifle platform developed to combine the best features of the HK G36 and HK416 into a single, next-generation weapon system. Unveiled in 2017, the HK433 was designed from the ground up as a highly configurable platform that can be rapidly adapted for different roles, from close-quarters combat to designated marksman duties. The rifle employs a short-stroke gas piston system with a rotating bolt, and features tool-free barrel changes that allow operators to switch between barrel lengths ranging from 11 to 20 inches without armorer-level tools. All barrels are cold hammer forged and chrome lined with a 1:7 inch right-hand twist. The HK433 accepts standard STANAG magazines and features fully ambidextrous controls including the charging handle, magazine release, bolt catch, and fire selector. A 7.62x51mm NATO variant, designated the HK231, has also been developed as part of H&K's two-caliber armament concept.
Specifications
| Weight (empty) | 3250 g (114.6 oz) |
| Weight (loaded) | 3750 g (132.3 oz) |
| Overall Length | 880 mm (34.65") |
| Folded Length | 690 mm (27.17") |
| Barrel Length | 406 mm (15.98") |
| Action Type | Gas Operated Short Stroke Piston |
| Firing Mechanism | Rotating Bolt |
| Trigger Type | Single Stage |
| Magazine Capacity | 30 rounds |
| Magazine Type | Detachable Box |
| Muzzle Velocity | 920 m/s (3018 fps) |
| Muzzle Energy | 1690 J (1246 ft·lbf) |
| Effective Range | 500 m (547 yd) |
| Maximum Range | 3600 m (3937 yd) |
| Rate of Fire | 700 rpm |
| Barrel Rifling | Right Hand |
| Rifling Twist | 178 mm (7.01") |
| Number of Grooves | 6 |
| Frame Material | Aluminum Alloy |
| Barrel Material | Cold Hammer Forged Steel |
| Stock Material | Polymer |
| Finish | Matte Black |
Calibers
- 5.56x45mm NATO · primary · 5.56x45mm NATO — also known as 5.56mm NATO, 5.56x45mm, .223 Remington
- 7.62x51mm NATO · 7.62x51mm NATO — also known as .308 Winchester, 7.62mm NATO
Features
- Firing modes: Semi Automatic, Full Automatic
- Feed systems: Detachable Box Magazine
- Safety mechanisms: Ambidextrous Safety, Firing Pin Safety
- Features: Modular Design, Tool Free Barrel Change, Cold Hammer Forged Barrel, Picatinny Rail, Adjustable Stock, Folding Stock, Ambidextrous Controls, Stanag Magazine Compatible, Suppressor Ready
Variants
- HK433 11" (Compact) — Compact
- HK433 14.5" (Standard) — Standard
- HK433 16" (Rifleman) — Standard
- HK433 20" (DMR) — Dmr
- HK231 (7.62 NATO) — Caliber Variant
Service history
Operators
- German Bundeswehr · as HK433
- German Federal Police
Production
Production years: 2017-present
In production for evaluation by multiple NATO forces; exact production numbers not publicly available.
Origin
Country of origin: Germany
Notes
The HK433 was developed partly in response to the German Bundeswehr's search for a G36 replacement after controversies about the G36's accuracy in hot conditions. The modular architecture allows barrel lengths of 11, 14.5, 16, and 20 inches, with the 20-inch variant serving as a DMR configuration. The 7.62 NATO version (HK231) was confirmed at AUSA 2017, using HK Gen3 polymer magazines compatible with DPMS-pattern interfaces. At Enforce Tac 2026, HK showed the HK433 MARS (Modular Assault Rifle System) and a PDW variant, indicating continued development of the platform.
Background
The HK433 was born from the political fallout of the G36 accuracy scandal, when the Bundeswehr demanded a replacement that could handle sustained fire without degradation. H&K's answer combined the proven gas piston of the HK416 with the ergonomic modularity of the G36 into an entirely new platform.