White Sound Defense Review

White Sound Defense FOSSA-556 Flash Hider Review

By Echo Foxtrot 

Photo Credits: Jody Lewis (Crossfire Photography) and Echo Foxtrot

Editor’s Note:

This review was not conducted in a controlled environment using lab equipment and is a representation of Echo Foxtrot’s views, based off his experience with the flash hider as well as similar products in the past. For lab testing and product specs please contact White Sound Defense.

FOSSA-556, named after a cat-like, carnivorous mammal endemic to Madagascar.

Lets get to the “meat” of it.

White Sound Defense describes the FOSSA-556 as a high performance multifunction muzzle device optimized for the fighting rifle. It suppresses muzzle flash and vents gasses away from the ground to limit dust disturbance. It also helps limit muzzle rise and reduces recoil getting the shooter back on target faster, all without increasing concussion or noise.

Lets Talk Specs:

  • Made from 17-4PH stainless steel
  • Available in titanium aluminum nitride or black oxide military grade surface coating
  • 5” x 28 tpi thread
  • Made for .223 / 5.56 Caliber weapons
  • Length 2.18”
  • Weight is approximately 3.1 ounces
  • Current series (002) is compatible with GEMTECH HALO suppressors

Some Key Features:

  • Effective Flash Reduction
  • Mitigated Dust Signature
  • Compensated Muzzle Rise
  • Reduced Rearward Recoil
  • No Increase in Concussion or Noise
  • No Ringing Sound

White Sound Defense stated that it is imperative that a muzzle device on a fighting rifle reduces flash to the lowest possible level. Muzzle flash that is visible to the enemy will draw fire. The brighter the flash the greater the distance it will draw fire from. A compromise on muzzle flash brightness is a compromise on position disclosure.

The second priority is to improve the effectiveness of fire. Muzzle climb is countered by redirecting propellant gasses with an upward bias.

How is this done you ask? The vents on the device decrease in width by about 25% over their length. This narrowing acts as a choke forcing the propellant gases to vent to the sides rather than continuing forward. When installed correctly with the widest tine at the 6 O’clock position the gas pressure will push on this lower tine reducing muzzle rise. The central bore geometry and angle of the vent walls are also designed to assist in pushing gases to the side. The recoil reduction is approximately half of what you get from a competition style brake, but without the noise or concussion. That includes ringing. That’s right no ringing sound. The tiny holes in the end of the muzzle device help to change the resonate frequency.

The most important question of all, what does it mean to you the consumer? Great question. Its simple, it is exactly what White Sound Defense said it was. What? Wait? How can this be?


Companies sometimes boast and tell little white lies about their product to get more sales. Not here. I ran the FOSSA through its paces and found the flash suppressing capabilities to be amazing. There was little to no visible flash that I could tell. I recorded it on my Go Pro and played it over and over. There was so little of a signature that it was difficult for me to locate the muzzle as I watched. Hell I planned on adding the video to this article but it’s basically just a black screen.

The muzzle rise compensation was great as well. My weapon stayed balanced on both the vertical and horizontal plane. Going prone is no problem. With the large tine on the bottom it mitigated the dust signature leaving your vision clear for follow-up shots (depends on the soil testbed). With the gases being allowed or forced to the sides the recoil is moderately controlled, based sold off my non-technical testing. And what was that you read earlier? No ringing? That’s correct.

The mad scientist at White Sound Defense figured out a way to fix the harmonics. On other devices I was able to clearly hear the ringing with my electronic hearing protection. Not here. The FOSSA is also not what I like to call a buddy F*&%#$. This is that muzzle device that treats you well but just about kills the guy next to you on line with the concussion blast. You know the type; you can feel it in your teeth as you read this. Well not here.

It’s surprising to me how long this product has been on the market and yet its not mentioned with the “big boys”. I have reviewed a lot of muzzle devices, a lot of big names and this White Sound Defense FOSSA 556 more then stands up. There have been other reviews on the FOSSA and even Frank Proctor gave his endorsement for the FOSSA stating:

“I get to see a pretty big variety of muzzle devices in my courses and I was very impressed with what I saw or didn’t see with the White Sound Muzzle device.  It produced zero visible flash signature with all the ammo we put through it and it doesn’t ring like a lot of the 3 prong devices out there”.

But even with such telling words from an amazing instructor there is little fanfare. The FOSSA 556 goes for around $100. Not the cheapest on the market but in my opinion worth it, a great addition to your weapon system.

White Sound Defense did it right with the FOSSA-556. They have created a product that delivers on all fronts and gives the consumer exactly what it said it would. Oh and its made right here in the great USA.



Check out the FOSSA- 762 as well 




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