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Damaged MFI SIG 550 & 551 Style Flash Suppressor for SIG 556 / SUPER SALE

Designed specifically to fit the SIG 556 & SIG 522 Series Rifles & Pistols.


Limited Supply: only 6 remaining
Was: $42.00
Sale: $12.00
Save: 71%
Save: $30.00
5 5 1

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- SIG 550/1 & 552 Flash Hider Unde -
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Damaged MFI SIG 550 & 551 Style Flash Suppressor for SIG 556 / SUPER SALE

These got damaged at some point and the finish is below what we normally accept. Strictly cosmetic issues that can only be seen at very close range, like 3-4 inches away. Great value. Most have 1-3 hits while others have less or more. There is no hand select as I grab what is available. Some may also have tiny spots of rust. None are worse that you can see in the first photo.

The rest of the description is for the 100% good ones, but parts affect the damaged ones as well so I left the below in this description.

Muzzle Brakes are also known as: Flash Suppressor, Flash Hider, Flash Hinder & Anti Climb Device.

These are designed for LIVE FIRING.

We test all our Muzzle Brakes to be 100% sure that they function shot after shot without any problems.

MFI uses the term "Flash Suppressor" ONLY in reference to the shape / look that our Muzzle Brakes have as they are designed to mimic the external appearance of their Military Counterparts.

This product fits any weapon with a threaded barrel in 1/2 X 28 tpi.

Fits All SIG 556 & 522 Style Rifles & Pistols:

  • SIG 556 Standard Rifle
  • SIG 556 Patrol Rifle
  • SIG 556 SWAT Rifle
  • SIG 556 Pistol
  • SIG 556 Classic Rifle
  • SIG 522 Standard Rifle
  • SIG 522 Pistol
  • CDNN SIG 551A1 Rifle
  • West Coast Armory SIG 551 Rifle

SIG USA does NOT supply any of their rifles with Flash Suppressors that look like the Original SIG 550 / 551 / SIG SAN / SWISS SIG. Even if you could find an original flash suppressor it would be impossible to mount to the SIG USA rifle or pistol without major modification.

This Flash Suppressor / Muzzle Break WILL allow the use of a standard US / NATO style bayonet (M7, M9 or M11). This flash suppressor has an added 6th cut / slot (originals had 5 slots with lower section being filled to deflect flash). This way you do not need a peel washer to index the FS to the correct location. The peel washers always created a problem in terms of looking incorrect as well in that the original SIG 550/1 flash suppressors were machined in the barrel and thus not removable.

The Flash Signature of the MFI 550/1 & 552 Flash Suppressors / Muzzle Brakes are comparable with original.

NOTE: SIG 556 Rifles & 556 Pistols have the SAME THREAD PATTERN as .223 caliber AR15s / M16s which is 1/2 X 28. This is the same thread pattern we use for this product.

NOTE: As these have uniform flash cuts / venting slots 360 degrees around there is no need for a peel / crush washer.


  • 100% Made In the USA.
  • Weapons Grade Steel / Mil. Spec.
  • Heat Treated to about Rockwell 34.
  • Threaded 1/2 X 28 tpi. This will fit any AR15 in .223 as well.
  • Crush / Peel Washer NOT required.
  • Weapons Grade Steel / Mil. Spec. Black Oxide to be a close match to USA SIG barrels.
  • As close a copy of the original: We spared no expense to get these absolutely correct.
  • Tolerance held is + / - 0.001 (less than the thickness of a piece of paper).
  • WILL allow the use of a standard US / NATO style bayonet (M7, M9 or M11).
  • Cost Effective: Highest Quality at the lowest price is always our goal. We achieve this by making these in high volume. This equates to greater profits for distributors and re-sellers. Nothing else on the market compares in versatility, quality and cost effectiveness.

No FFL needed, No Special License, No Permit Required & No Special Tax Stamp needed to order.


In accordance with the Joe Biden & Beto O’Rourke directive I personally as well my company no longer own(s) or possess any firearms or ammunition. This includes but is not limited to: Handguns, Pistols, Shotguns, Rifles, NFA items, Hog Legs, Fire Sticks, Smoke Poles and or Thunder Clubs.

All firearms that appear on our web site, regardless of what is written about them, are not owned by the company nor possessed by anyone associated with MFI and may even be CGI / PhotoShop.

Therefore regardless of any new firearms laws / taxes, no probable cause can EVER be assumed on any property (stationary or mobile) owed by myself or MFI.

AGAIN: We are 100% in compliance with any possible new “Biden / O’Rourke Public Safety Act” and therefore NO PROBABLE CAUSE could ever be assumed.

Lastly anyone arriving with a warrant of any kind will be assumed to be an IMPOSTER with intent on murdering us and will be treated as such without warning.

Those invading our territory may receive serious and even fatal wounds from rusty blades, clubs with bent nails, spear tips, arrows and or crossbow bolts.


This item is NOT RESTRICTED FOR DOMESTIC US SALES in any way and we offer DOMESTIC USA shipping to ANYONE. We ship to all 50 US States as well as all US Territories i.e. Guam & Puerto Rico. Sorry we can NOT ship to ANY APO address regardless of actual location.

This item is 100% RESTRICTED FOR EXPORT OUTSIDE THE USA. The US Department of State regulates / restricts this product and it is NOT EXPORTABLE outside the USA even to LE, Governments or Military without State Department approval.

This approval is AVAILABLE through MFI as we are an ITAR / Dept. of State Registrant with the Directorate of Defense and Trade Controls Office. We can obtain a US State Dept. Export License for you.

Please feel free to contact us if you have any questions on this issue.


  • SIG-550-FS
  • SIG-550-FS
  • MFI
  • Available
  • New

Shipping Information

  • Item Requires Shipping
  • 0.3 lbs.
  • $2.45

Customer Reviews

Comment Total Reviews (1)

Perfect for my needs.
  • Currently 5/5 Stars

Reviewed by:

Product ownership: Less than 1 year

Purchased from: MFIAP.COM

Super cheap and you cannot see the issues without being within 8" or closer. Super fast and cheap shipping too!

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