San Tan Tactical STT-15 Billet Lower Receiver

  • - Huge 1.38” Integrally Machined Magazine Well Flare
  • - Ambidextrous Quick Attach \Detach Sling Swivel Points With Anti-Rotation Stops Every 45 Degrees.
  • - Ambidextrous Bolt Release.
  • - Ambidextrous Magazine Release.
  • - Bullet Pictogram Safety Selector Markings.
  • - Set Screw Trigger Creep Adjustment.
  • - Set Screw Upper Take Down Tension Adjustment.
  • - Shooter Ready Finger Rest.
  • - Oversized Winter Trigger Guard.
  • - Dowel Screw Assembly.
  • - Ultra Grip Texture On All Controls.
  • Model:
    STT-15 L
  • Caliber:
    5.56 NATO \ .223 REM, 300 BLACKOUT, 22LR, Multi-Cal, Custom Caliber Markings Upon Request
  • Action:
  • Weight:
    9.4 Ounces /268 Grams With Ambidextrous Controls 8.4 Ounces / 238 Grams Without Ambidextrous Controls.
  • Dimensions:
    Length: 7.69” Width: 1.490” Height: 4.015”
  • AMaterial:
    Billet 7075-T651 Aerospace Grade Aluminum, Cast A-2 Tool Steel
  • Finish:
    Aluminum – Matte Black MIL-A-8625 Type III Hard Anodize, Steel – Black Oxide
  • Butt-Stock:
    Works With Any Mil-Spec or Commercial Buffer Tube and Stock.
  • Magazine Compatibility:
    (Lock In, Drop Free Additional Magazines Will Be Added As Tested) 100 Round Beta Mag, 100 Round Surefire,60 Round Surefire, 30 Round Magpul P-MAG Any Generation, 20 Round Magpul P-MAG Any Generation, 10 Round Magpul P-MAG Any Generation, 30 Round Mil- Spec Mag, 20 Round Mil-Spec Mag
  • Component Compatibility:
    Works Will All Mil-Spec AR-15\M16 Components*.

*Excluding proprietary ambidextrous controls.

The lower recieve will work with standard milspec parts bellow is what we currently recommend.
Part No. Description UPC
14037 16" Barrel 816715012463
14037 Some Upper 816715012463
14037 Some other Upper 816715012463
  • Who makes the STT-15 and all of its control parts for you?
    We do! STT makes the lower and all of the controls right here in Chandler Arizona, in house.
  • Will your lower accept a Mil-Spec lower parts kit?
    The STT-15 is 100% compatible with any Mil-Spec lower parts kit. You will have a few extra parts as STT includes the ambidextrous bolt catch assembly and the ambidextrous magazine catch assembly with your new lower receiver.
  • Is it difficult to assemble the STT-15? It has different controls than I am used to on my other lowers.
    The STT-15 comes fully assembled! This allows us to check and guarantee fit and function of every lower receiver that leaves San Tan Tactical.
  • What parts will I need to complete the STT-15?

    If you have a Mil-Spec LPK you already have more than enough. If not and you would like to get each of the parts you will need separately, here is a list.

    Front & rear takedown pins with springs and detents.
    Safety selector with spring and detent
    Fire control group with pins
    Buffer assembly including castle nut, end plate, buffer tube, action spring, and buffer.

  • What are your lowers made out of?
    Our lowers are CNC machined directly from a single block of 7075 T-651 Aerospace grade aluminum.
  • Are the controls on the STT-15 cast or machined?
    We machine them directly from a billet of A-2 Tool Steel.
  • How does the STT-15 Lower Receiver compare to ________’s lower receiver?
    Some would say we have a biased opinion however just compare the features the STT-15 includes. If you would like please feel free to contact us to talk about it and we can answer any questions you may have.
  • Will the magwell on the STT-15 accept USGI, Magpul P-mags, Surefire or Beta C-Mags?
    It will! We designed the lower to give you the widest and deepest possible magazine well flair while maintaining full magazine compatibility.
  • Will the STT-15 Lower receiver work with the _______ upper receiver I currently have?
    Absolutely. The STT-15 will accept ALL Mil-Spec AR-15, M4, M-16 components. Excluding the included ambidextrous controls of course.
  • Do you have a build out list for _______ rifle I see on your website?
    We do! Please contact us and let us know which rifle you are looking for specs on and we can send the build out list out to you.
  • Do you offer the STT-15 as a stripped lower only or can I get a complete lower package?
    We are currently building a configuration page on so you can customize your new rifle to your liking. In the meantime please contact us so we can spec out your new complete lower receiver.
  • Does San Tan Tactical currently have lowers in stock?
    Our website has live inventory. If it is in stock that means it is ready to go! Our goal is to ship all orders the same or next business day at the latest!
  • What is the warranty on the STT-15?
    Our warranty is simple. We will do whatever it takes to make sure our customers are completely happy with their new purchase. If for any reason something isn’t meeting your expectations please contact us immediately so we can get it taken care of right away!