For sale is a fully transferable, legally registered H&K G3-to-HK21 machine gun conversion, transferable to individuals on a Form 4 (or Form 3 for dealers). This listing is for a registered machine gun, not a parts kit. It has been professionally built and runs reliably as a belt-fed HK21 pattern MG. Excellent opportunity for NFA collectors seeking a transferable HK-pattern belt-fed platform.

⚠️ All NFA rules apply. Buyer is responsible for verifying eligibility and completing transfer procedures.

Key Details:

  • Type: Transferable Machine Gun (HK G3 → HK21 conversion)

  • Caliber: 7.62×51 NATO / .308

  • Platform: Belt-fed HK21 pattern

  • Registration: Fully transferable; currently on Form 3 

  • Action: Roller-delayed blowback

  • Condition: Used — Good 

  • Function: Runs reliably; tested 

  • Includes:
    • HK21-style feed mechanism
    • Extra barrel and parts kit

1-200rd MG3 belt with ammo surplus M80

3-50rd M13 links with starter tabs

2-50rd MG3 belts 

2-100rd MG3 link belts

Niche Tactical MG3 belt loader

1-Extra Barrel

2-Belt Feeder Mechanisms Complete 

1-Saw Parts kit minus barrel (trigger pack, bolt, bipod,stock and receiver section)

Custom AA HK21 Tripod from Beltfed Shooter Mounts

Willing to trade for a .30 1919 plus cash