Sightlink Fiber Optic Front Post:

Sightlink - AR-15 Fiber Optic Front Sight: MSP Scope Mounts

Sightlink mounted in Daniel Defense Front Fixed BUIS:



For pistols, I typically paint my front sights red using Testors model paint under magnification using loupes for a nice ‘sharp’ sight picture. This has served me well in competition and is good enough for my carry platforms.

Recently, I’ve been experimenting with fiber optic sight options for the front only as I still believe in a plain black rear notch/aperture, to focus the eyes quickly to the front sight. Having acquired a M&P15-22 recently as part of my recent foray into .22 rimfire shooting, I have also discovered how much fun steel shooting can be using this rifle. Still in denial about my failing eyes and not wanting to have to shoot in ‘open’ division, I’ve been looking for fiber optic options for this rifle.

The Sightlink AR front sight post pictured above is probably the best solution for a contrasting front sight available for the AR platform. It comes in three (3) widths along with extra FO rods to change the color to your liking, assuming you are willing to do a little cutting and heating with a lighter.

The feature that sets this FO front sight post apart from the rest is the ability to fine-tune the elevation. This is made possible by the dual independent rotating detent bases that allows the elevation to be adjusted 4-clicks per revolution, AND the FO blade to be clocked properly independent of the elevation. The blade is designed so that one end has a smaller/finer glow, while the other is a bit larger/brighter by virtue of how the FO rod is secured to the blade.

Another popular FO front sight post only has a single base which uses a u-shaped rod, so you are limited to only two clicks per turn to get the elevation in the ball park. Remember, the standard AR post is just a post, so no matter where the elevation is set (4 or 5 detent base) the front post looks the same. These FO front sight posts require some length of rod to gather light, and hence have some form of a blade which needs to be oriented parallel with the barrel.

I’ve installed and tested the Sightlink on the S&W OEM fixed front BUIS, a Daniel Defense fixed front BUIS, a LMT fixed front BUIS as well as a Colt FSB/gas block with no problems.

NOTE…..depending on the front sight, you may need to cut down the supplied detent pin to allow the front sight to rotate all the way down, if you need that range of adjustment. This is especially apparent in the folding-type front sights as these sight use a shallower hole for the detent pin and spring.

The Daniel Defense fixed front sight also had a shallower hole for the detent so the detent pin in this application needed to be cut. An easy job with a cut off wheel, followed up with some polishing.

One other caveat: not all folding front sights sit deployed straight up exactly at a 90’ angle. I tested this on an ARMS folding front sight (the polymer one) and noted that the front sight tower rests deployed at an angle LESS than 90’. Since the Sightlink front sight is not a narrow post but a blade, the top of the sight had a bit of blurriness when viewed through the rear sight. I noticed that my metal ARMS folding front BUIS also exhibited this trait.

Also NOTE……you must ensure that whatever front sight you plan on installing this in, that the detent pin rests at 12/3/6/9 o’clock to ensure proper clocking of the blade. I was about to purchase a set of LWRC Skirmish folding BUI sights but noticed in some stock photos that the detent pin was located at a 45’ offset. According to LWRC, this was done as a matter of design specific to the Skirmish front BUIS. Such a setup would leave you with a front blade skewed no matter how you turned it.

For you 10/22 shooters using the excellent Tech-Sights rear aperture and front AR post system, the Sightlink works as a direct replacement for the Tech-sights front post, but you must use the detent pin that came with the Tech-Sights post as it uses a very narrow detent pin.

I have had much success using this FO front sight at some local steel matches, and intend to put it through some vigorous testing next week at the Ruger Rimfire World Championship match.

Dave

Nice review, thanks for posting. I will be trying one of these out very soon!

pretty detailed write-up. i dont run iron sights but i wonder if these work in magpuls?

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od: xd9 3"&4", 15-22, 1911 .22

Excellent review, thanks for sharing. The Sightlink Web site offers three choices: .070 Military Spec, .060 Match, .050 Ultra Match. Any suggestions?

I'm running the 0.070" Military width (same as standard AR post) on my M&P15-22. Since this rifle is for fun and speed, I wanted to get the biggest diameter FO rod possible. Using the large aperture, both eyes open with daylight, the 'dot' glows nicely over targets, but has enough metal on the top edge for aimed distance shooting.

I also have the 0.050" wide Ultra Match on my 10/22 using the Tech Sights front and rears. Using the 0.042" and 0.062" aperture inserts, it gives a wonderfully sharp precise sight picture, but has enough glow for adding some speed to shooting.

I like RED contrasting front sights (paint or FO) for pistols and rifle. I use GREEN for my smooth bores used for trap and sporting clays.

You will need to verify the position of the detent pin in your specific front sight housing. As long as it is at 12/3/6/9 o'clock, you're halfway there.

Sightlink supplies two detent pins (longer to engage BOTH notched bases) of different diameter as the diameter of the housing for the detent pins differ among manufacturers. You need to pick the one that fits snug without binding.

Then, depending on how deep the housing is drilled to accept the spring and detent pin, you may need to shorten said detent pin to allow for an acceptable range of adjustment, specifically, how low you can screw down the sight, to raise POI, if your REAR has no elevation adjustment.

In some polymer front sights, the housing may be 'rough' which may impede the movement of the detent pin - you may need to do some smoothing with some finishing carbides.

In one of my test installations, I also polished the outside of the detent pin (larger diameter pin fit too tight and small was too loose) removing a few thousands of metal to allow it to slide w/o resistance. Luckily, the small diameter portion of the detent pin chucked into my electric handpiece so that was an easy job.