MFI SIG 556 Rear Diopter Sight & Rail with SIG SANs 550 / SG 551 Style Hooded Front Sight with Fiber Optic
Latest Production Run!
New Lower Price
due to higher volume manufacturing.
After years of RND and production difficulties I am happy to say that we have finally gotten to where I wanted to be in terms of quality and price. As many of you know it has taken us 8+ years
to get to this stage.
The price you see above reflects the "Non Fiber Optic Version"
with a Front Hooded Sight and all attachment hardware included.
What you see in the first picture is what you get in this set.
- 1 - Black Diopter + Rail (with Fiber Optic)
- 1 - Hooded Front Sight (with Fiber Optic)
- 1 - Allan Wrench (for rail bolts)
- 1 - Front Sight Windage Wheel, Nut & Roll Pin
- 3 - Rail Bolts
If you want fiber optic or a different front sight you need to choose from this link which shows you all the Diopter sight options:
This product is a True Plug & Play
item. Just unscrew the 3 bolts that hold your rail on and place our rail on in it’s place. There are no small metal tabs or shims to lose as ours is 100% self contained. We also provide 3 replacement bolts and an Allan Key Wrench.
The Rear Diopter Sight had to be connected to a rail in order for it to be low enough
to line up with the ultra low profile of the Original Swiss SIG SANs Front Sights
. Yes you can use the Original PE90 / 550 / 551 / 552 / 553 Swiss SIG Front Hooded or Non-Hooded Sights. You can NOT
use the SIG 556 USA Hooded Front Sight or any other sight on the market except
our MFI SIG SANs Hooded or Non-Hooded front sights.
MFI REAR Diopter Sight & Rail:
I designed these to look like the original SIG PE-90 / SG 551 rear diopter sights that were welded on to the receivers. The parts are NOT
exact copies of the originals... Meaning that the parts of the MFI Rear Sight are NOT
interchangeable with the original Swiss SANs parts. The design did not allow this and it was more cost effective to not even try.
The Rear Diopter functions basically like the original
and has near exact markings as the Swiss SANs sight housing. The numerical markings on the Drum / Diopter are also an exact copy of the original with the exception of the #4 which we changed from white to red... it just looked cooler.
As I am not
a huge believer in the accuracy of the .223 / 5.56mm cartridge so I only fully tested the number 1 position at 100m. The #2, 3 and 4 designations may or may not be applicable. I did position the holes in the correct location, but I did not waste time or funds to test something I do not really believe in. While the #2 and #3 holes are the right size and position the #3/4 position hole is much smaller
than the original and is NOT
threaded for the insert of a target peep sight, nor is it likely to be at the correct angle as I do not have one to check against. The Diopter walls have not
been counter bored on the inside
either, so the walls are thick in that area to accept a thread. As I said... The hole is much smaller
so that the customer could MILL a new hole
at whatever angle they need and make it work. Sorry you are on your own on this one
... just not cost effective
to test / check 100% when 99% of the customers will never have the money to buy a SIG SANs target peep sight much less have the need to use it.
Fiber Optic Option:(Again NOT included with this set)
The holes for the fiber optic option in the rear Diopter are also smaller
than the original. I did this so that you could buy the sight without the fiber optic
and drill the holes out to fit the Tritium Ampules / Tritium Inserts. Due to the short shelf life, cost and pain in the ass import regulations I have no intention
of ever offering Tritium anything for sale. Check the forums for suppliers.
Above is a photo showing you the two options side by side (with or without fiber optic).
Materials of Construction:
The Rail, Diopter & Diopter Sled are 4000 series cast aluminum.
The SIG 550 / SG-551 Style Hooded Front Sight is CNC Machined 7071 T-6 Aircraft Aluminum.
The Windage adjustment wheel & knob and other small parts are steel.
The Rear Sight & Rail are painted to match SIG 556 Black Finish. The Rear Sight is made from special 4000 series aluminum alloy to allow it to flow more consistently into a mold. Unfortunately the non-aluminum alloys used (in particular copper and silica) make it impossible to anodize
, so the rear sight and rail are painted like the originals
were. The rear sight housing and rail are near 99% finished when they come out of the mold. We tried to retain many of the casting marks and even simulated some of the grind markings found on the original sight housings. I am not
aiming for 100% perfection in a product as that is pointless and no cost effective. So if you have a safe queen that is worshipped rather than used... no MFI product is likely to live up to your standards.
At the front of the rail you will see a Swiss Style Cross and Shield
. Additionally we have shaped the front of the rail to have a similar cut out
that would normally be used for a scope mount, but in this case is strictly cosmetic
. I spend a lot of time on the finer points of the design as it is critical to make any product as cool looking
as possible. I hope you all approve.
3 – MFI SIG Top Rail Bolts and Allan Key
NOTE: Copying the original as closely as we did has it’s advantages and disadvantages. While we try to maintain the look and style of the original rear sight any deficiencies that exist in the original design will likely come through as well on the reproduction. A good case in point is the Windage Adjustment Knob. Originally designed to use a Swiss Franc Coin to adjust, even the original SANs sights get the paint chipped or the edges of the adjustment slot scratched or damaged in some manner. For this reason we recommend that you adjust the knob by hand (yes possible) to avoid damaging the finish of the knob. The next best option is to use a coin (dime) with thin tape on it. The coin is what was originally used as the slot is dished to receive the rounded edge of a coin and NOT the flat edge of a screw driver.
In this latest production we moved from a painted windage adjustment knob / screw to Parkerizing it and then cold bluing it for a chip free finish. Use of a screw driver or any sharp or incorrect size / shape tool can damage the slot.
MFI Front Hooded SIG 550/1/2/3 Sight: AVAILABLE
Here is a link for more photos, information, pricing to order separately and instructions on the installation of the front sight. Click on the "Instructions