AR-15 Quad Rail and Back Up Sights




Posted in WorkshopMetalworking

Introduction: AR-15 Quad Rail and Back Up Sights

I built a set of flip up sights and a free floating quad rail that interfaced with my Model 1 AR-15 to add an accessory rail that looks great and is functional.  I got many of the parts from but everything highlighted in blue in the main picture were parts that I designed and made.

I started by building any jigs needed.  The tricky part was cutting out the 45 degree angles on the sight clamps for the picatinny rails.  I built a 45 degree angle jig since I did not have any mitre tooling for the mill.  Then made temporary attachments for the sight pieces to attach to the jig.  I made the jig using some corner brackets and clamped that into the mill.  It made for a very nice jig.

The .pdf files show the parts that were created and any jigs needed to make all of these parts.

The quad rail was built as an assembly using 4-40 and 8-32 hardware holding it together.  It was then cerakoted black.  I used a 1/4" ball end mill to smooth the transitions between angled surfaces.



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    Great work! Any desire to make me a set of sights??

    That is pretty sweet. Did you make the gas block as well? Also, how much would you estimate this to cost... doing yourself.. and having a machine shop doing it for you?

    1 reply

    I didn't make the gas block.. thought about making a low profile one and extending the quad rail over it.

    I would imagine that paying a machine shop to do it for you would be quite expensive. If you have access to the tools and some scrap aluminum then you can likely do it yourself if you are confident with the machining. If I were to figure out my time into this thing and calculate at $10/hour labor cost, I'd imagine that it cost me well over $150. Any shop would likely cost $1000 for a one off prototype like this.

    I mostly did it for the fun of doing it myself and had access to someone who could do the coating on it for free.