F4-15 AMBI Builder Set

(4 customer reviews)



The F4-15 Builder Set provides a solution for the DIY community; those that want to build themselves or take their time selecting components and just want the foundation of a precision rifle build.  We provide the F4-15 Receiver Set and rail system.

For an additional charge, Cerakote is available.  When checking out provide Cerakote color in the ORDER NOTES or call (240-808-2314) and/or email (info@f4defense.com) your instructions for more complicated Cerakote finishes.  We will send an invoice separately for the Cerakote.

Lead time: 3-5 weeks for Cerakote.



SKU: F4-15-BS-1 Category:


Technical Specs

  • Material: Precision CNC Aerospace Aluminum Matched Billet Set 7075-T6
  • Adaptive Rail System (6.5, 9, and 15.8 inches) or Adaptive Rail System – Lite (15.8 and 15.5 inches Flat Front)
  • Finish: Type III Class II Anodized Black or Cerakote (Invoiced Separately)




Additional information

Weight 4.5 lbs
Dimensions 18 × 12 × 6 in
Handguard Length

15.5" Flat Front, 6.5" ARS, 13.6" ARS-Lite, 15.5" ARS, 15.5" ARS-Lite, 9" ARS

4 reviews for F4-15 AMBI Builder Set

  1. CinemaFPS

    I was hesitant on placing my order originally, but Dave’s immediate correspondence as well as product/industry knowledge made me extremely confident in my purchase. His quality control and attention to details is unmatched. F4 has been extremely helpful and addressed all my concerns.

  2. joshua harrison (verified owner)

    Great Service throughout process. The set I received had excellent fit and finish. i was very pleased with the purchase

  3. Dave Fein

    Couldnt be happier finish and fit was fantastic and very affordable to get cerakote finish of choice. and ambi features is an added bonus

  4. alindo32 (verified owner)

    I normally only purchase from well known brands with a lot of reviews. I was a bit nervous giving this company a try with so little info to go off of. I am so glad I did! The set is beautifully finished and very well machined. I payed extra for the battleworn Cerakote to color match the Magpul OD green and they did a beautiful job. As much as I love this set, I was even more pleased / impressed with the customer service. They have been quick to respond to every email and even took the time to patiently help me over the phone with troubleshooting a mistake I made with the assembly. I would recommend and buy again. Great job, F4 team! Thanks again for the help and extra set screws, Dave.

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