How billet AR-15 receivers are made

Steve Johnson
by Steve Johnson

SI Defense manufactures AR-15 lower and upper receivers that are machined out of solid aluminum billet blocks.

Two soon-to-be receivers being sprayed with coolant by the CNC machine

They have photos of the process and a video showing the CNC machine in operation. Very interesting.

Thanks to Health for the link.

Steve Johnson
Steve Johnson

I founded TFB in 2007 and over 10 years worked tirelessly, with the help of my team, to build it up into the largest gun blog online. I retired as Editor in Chief in 2017. During my decade at TFB I was fortunate to work with the most amazing talented writers and genuinely good people!

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Join the conversation
  • Jdun1911 Jdun1911 on Feb 26, 2009

    They should take full advantage of the billet 6061-T6 aluminum. It allows interesting designs to be produce.

  • Heath Heath on Feb 26, 2009

    I'd like to have one billet lower just because of the cool factor!