• Comes with F1 Firearms Ambi Safety Selector
  • Made in the U.S.A.


  • AR-15 lower receivers


  • 1x Takedown Pin
  • 1x Pivot Pin
  • 2x Takedown/Pivot Pin Detent
  • 2x Takedown/Pivot Pin Detent Spring
  • 1x Bolt Catch
  • 1x Bolt Catch Plunger
  • 1x Bolt Catch Roll Pin
  • 1x Bolt Catch Spring
  • 1x Buffer Retainer
  • 1x Buffer Retainer Spring
  • 1x Magazine Catch
  • 1x Magazine Catch Spring
  • 1x Magazine Release Button
  • 1x F1 Firearms Ambi Safety Selector
    • 1x Long Lever
    • 1x Short Lever
    • 1x Center Core
    • 2x Hex Screws
  • 1x Safety Selector Detent
  • 1x Safety Selector Detent Spring
  • 2x Hammer/Trigger Pin

Note: This is “NOT” a complete lower parts kit. This is a builder’s kit. This Kit does not include the Pistol Grip, Pistol Grip Screw and Washer, Trigger and Hammer, Trigger and Hammer Springs, Disconnect, Disconnect Spring, Trigger Guard and Roll Pin.


Whether it’s your first advanced build or you’re an experienced armorer, F-1 Firearms AR-15 Gun Builders Kit is the easy way to complete your AR-15 lower receiver with quality internal parts you can count on. When you want to get your lower built with as little fuss as possible, this go-to kit will make your build a success.

Quality Essential Parts in One Package

One of the most tedious parts of building a new rifle is ordering all small lower receiver internals. Not only do you have to track down all of the separate groups, but if you want to have a reliable firearm when you're done, you can't order just anything from just anybody. It used to seem like in order to get the best parts for your build, every detent pin and spring had to come from a different manufacturer.

Problems with certain AR-15 parts were notorious. The industry tried to address them. Everyone concentrated on a different weak spot, but nobody offered a complete set of lower internals that dealt with them all. Thanks to the F-1 Firearms AR-15 Gun Builders Kit, that problem is history. F1 Firearms has created a builders kit of lower receiver internal parts, packaged them in labeled them in its packaging to streamline the assembly process, and added its ambi safety selector.

Don't Waste Money On Parts That You Have To Switch Out

The standard trigger group and pistol grip were first replaced when someone is upgrading their AR-15. When you choose the F-1 Firearms AR-15 Gun Builders Kit, you don't waste money on components that you will eventually toss away. You get all of the AR-15 parts you needed to start a quality working lower receiver, add a trigger group and pistol grip of your choice, and you can breathe again. No more mental jigsaw puzzle and checklist of part numbers, making sure you get everything ordered. No digging in a box full of pins and springs to catch the right ones for the stage of build you're in. Take the shipping box to your workbench and take out what you need, one neatly packaged group at a time. Assemble in record time. Spend your time at the range, not on the phone or at the workbench.

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