This is the factory Heckler & Koch buffer spring for the HK416, also listed for the MR556A1. The buffer spring returns the bolt carrier forward after each shot. Replace it when it has lost tension. Compare it with your existing part or the manufacturer's parts diagram to confirm it matches your firearm before ordering.
- Part: Buffer spring
- Fits: HK416 / MR556A1
- Brand: Heckler & Koch
- UPC: 642230247840
