The HK21 is a belt-fed firearm platform developed by Heckler & Koch and based on elements of the company’s roller-delayed firearm designs. Introduced during the latter half of the twentieth century, the HK21 became notable for combining a belt-fed configuration with the engineering characteristics associated with the broader HK rifle family.
Component
| Component | Specification / Description |
|---|---|
| Platform | HK21 |
| Manufacturer association | Heckler & Koch |
| Component type | Parts kit |
| Operating-system association | Roller-delayed platform |
| Component collection | Original, surplus, or mixed components depending on kit |
| Receiver components | Configuration dependent |
| Barrel components | May vary by kit |
| Bolt components | May vary by kit |
| Feed-system components | HK21-specific components, depending on completeness |
| Furniture | Configuration dependent |
| Sights | Components may be included depending on kit |
| Small parts | Varies according to kit contents |
| Finish | Varies by component and condition |
| Markings | Factory, military, or surplus markings may vary |
| Origin | Varies according to component provenance |
