Utilizing OSS Generation V Flow-Through™ technology, the HELIX™ Line delivers unmatched signature reduction, modularity and economy for tactical, professional, hunting, and sport shooters.

The latest addition to our HELIX line, the HX 556 is an integrated flush mount system built with titanium, stainless steel and cobalt.  The HX 556 dramatically reduces backpressure, blowback, sound and flash signature, and is full-auto rated.  A self-tightening mounting device – the STS-Muzzle Brake – is included.

With the purchase of additional STS-Muzzle Brakes, the HX 556 can be quickly switched between your 5.56  guns. Just thread the HX 556 onto the STS-Muzzle Brake, hand tighten and you’re ready to shoot.


  • Diameter: 1.75"
  • Length: 6.8"
  • Weight: 20.8oz
FFL Address Required Yes
Shipping Class
Suppressor Yes

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OSS Helix 5.56 (HX 556)

  • Brand: OSS
  • Product Code: HX 556
  • Rating:
  • Availability: In Stock
  • $1,189.00