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MFI SIG 556 / 550/1/2 Front Flip Up Sight / Price Includes S&H via USPS 1st Class Mail.

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


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MFI SIG Front Flip Up Sight:

MFI SIG 556 / 550/1/2 Front Flip Up Sight

SORRY, I ran out of the assembled Narrow Front Sights, so now the set is automatically the Fiber Optic with a SPARE Narrow Sight Blade. You can swap out the sight blades by punching out the roll pin. I do not have spare roll pins and I do NOT offer the swap.

  • 2 - Blade Options: (You get 1 with the sight)

  • Spare / Extra Front Sight Blades are available separately. Click the above links / types.

    This is our version of the Original SIG USA Flip Up Sight that came on only a few of the first series SIG 556s. Most were "Optics Ready Models" only which meant that they had no sights at all, not even the in the rail nail file sight.

    If you own one of the original SIG USA Flip Front Sights you will know of it's many short comings. The worst issues all focus around the Blade. The Blade is too wide and covers too much of the target area. The Blade has very poor positive lock, meaning that it is either very hard to move or it flops up and down when the weapon is fired. The Blade can also be pushed (and it will stay) past the vertical up right position.

    We have solved these problems by holding a tighter tolerance and replacing the poor quality spring and detent with a standard AR15 set up. This allows the Blade to be moved up and down with easy, yet keeps it in either position that it was set in during firing. The detent is crisp and while you are able to push the Blade past the upright vertical position it automatically snaps back to the correct up right position once you let go.

    We have given the customer the choice of 2 different blades. One is the standard size but with a fiber optic dot inserted. The other is a blade that is narrowed at the top to a standard Target Width of 0.080" wide, which vastly improves your ability to see and track. It also allows the shooter to have a more pin point accurate choice of bullet impact.

    Unlike the original sight we have added a Center Alignment Marking to assist the shooter upon installation.

    Lastly we have made sure that all our parts are Iinterchangeable with the Original to allow the customers who already own a SIG 556 1st Series Flip Sight to replace their Blade with one of ours.


    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.


The MFI Flip Front Sight will Co-witness / Lines Up with:
  • MFI MAD / BUIS Rear Sight This is what it was originally intended to be used with.
  • Nail File Rail Sight of 1st series SIG 556 (pre-August 2009)
  • HK 416 Rear Sights for 16" barrel length (not pistol)

If you have a SIG Classic or SIG 556 built AFTER August 2009 the nail file flip up rear sight found in the top rail will match ONLY the height of the SIG USA front slanted hooded sight.

If you have a SIG USA 556 Rear Diopter Sight that ONLY lines up with the SIG USA front slanted hooded sight.

The MFI Front Flip Sight for the SIG 556 is slightly taller than the SIG USA front slanted hooded sight so if you wanted to use it with the SIG USA Diopter Drum Rear Sight you could as long as you either adjusted your sight picture or bought the Target / Narrow Blade version and cut off the top of the blade where it is narrow as that is the exact point where you need the blade to be.

As mentioned above you can also use the HK416 or Troy Rear flip sights / any rear rail sight that is the correct height for a HK416 as it just so happens (pure accident) the MFI Front Flip Sight is the same height as the HK416… I have not tested all the below sights, but there is one for the 10.5” HK416 and that may or may not be more applicable to your 556P…

  • Improved Positive Lock Up & Down.
  • Center Alignment Marking.
  • (Hex Key) Adjustment for windage.
  • Includes Front Sight Wheel / Bolt Windage Adjustment.
  • Weapons Grade Steel / Mil. Spec. Black Oxide Coating.
  • Heat Treated to about Rockwell 30.
  • 100% Made in the USA.
  • Photo is Actual Product.
  • Height: Flipped Down @ 0.525 Inches / 13.3mm (from the top of the Picatinny rail)

  • 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
  • Restrictions

    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.


    The front sight's dove tail must slide somewhat freely in the dove tail of the gas block.

    Meaning: You should NOT have to use a hammer to drift the sight side to side, but it should also NOT be so loose as to slide easily. The right amount of friction is so that the sight drifts sideways via a significant amount of force using your fingers... i.e. nearly all of your might using both hands(tightest) to as easy as half of your strength (loosest). The idea here is that the sight has enough friction in the dove tail not to move during firing.

    Failure to do this WILL result in the stripping of the cross-over bolt or the shearing of the roll pin inside the donut / round nut.

    Hand fitting is required as the dove tails in the gas blocks vary from production to production. Hand fitting can be done via a small hand file used on the slanted edges of the sight's dove tail.

    How to install the roll pin in the front sight.

    It is easy to mess up the roll pin when you first try to install it. Read below to avoid the pitfalls. Not all SIG 556 series weapons come with a front sight installed. So issues like this arise most often when the user is NOT first removing a similar front sight from the weapon and thus is completely unfamiliar with the requirements.

    There is a first time for everything and that is a part of any weapons system.

    When SIG installs these at the factory they have a special fixture or a second person to hold the weapon. While a fixture or third person is NOT required it sure makes it a lot easier. All you need is someone to hold the weapon while you hold the punch and hammer.

    Be sure that the hole in the donut and spline are clean / free of metal shavings.

    The most common mistake that leads to messing up a roll pin is not having the hole in the spline / adjustment bolt and the hole in the round / donut wheel lined up. You will have to use a punch or something to be absolutely sure of the alignment. Use a 1/16” punch or 1/16” drill bit or 1.5mm allen key… or look around the house and shop for something that fits through both.

    The number of turns to get the holes lined up is between 2.5 and 3 full rotations (you have to look down the hole). The windage bolt should NOT go past the point of being flush with the outside edge of the donut.

    It is a lot easier to file or grind down the roll pin at one end and then gently collapse the same end with a vice grips of pliers so that it just fits / sits in the hole of the donut. This will free up one hand. This is almost a requirement.

    Lube the hell out of the roll pin and hole of the donut and spline.

    Always start with your 1/16” punch (or whatever) 3/4 the way through to assure alignment. As you drive the roll pin in the punch will move out the opposite side.

    Good luck...

    These roll pins are specially made for us so, if you mess up the roll pin you can buy a spare from us on this page:


    Shipping Information

    • Item Requires Shipping
    • 0.1 lbs.
    • SHIPPING IS INCLUDED VIA USPS on orders over $82.00 Dollars AND OR If S&H is INCLUDED in the Title / Discription.

    Customer Reviews

    Comment Total Reviews (2)

    Superior Product Over OEM!!
    • Currently 5/5 Stars

    Reviewed by:

    Product ownership: Less than 3 months

    Purchased from: MFIAP.COM

    The design of this front sight is Perfect for replacement of the original. This is how Sig Sauer should have made it! This is also a perfect sight for the 556R wich doesn't come with a front open sight! High quality product much improved over Sig Sauer's original flawed design. Well worth purchasing, as you never no when your optic might fail then it's back to basics!

    Great Item!!!
    • Currently 5/5 Stars

    Reviewed by:

    Product ownership: Less than 3 months

    Purchased from: MFIAP.COM

    Works flawlessly! Super price too! Got Free shipping to boot!!

    You are the best


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