Unbranded AR Ambidextrous Lower Receiver

SKU: 7031-0115-0000

Click Here for Price
Out of Stock

This item is regulated, therefore your entire order will be shipped to an FFL dealer of your choosing. After you place your order, we will contact you to finalize these details.

AT3™ Pro-Builder™ AR-15 Lower Parts Kit - No Grip or Trigger Assembly

AT3 Pro-Builder Lower Parts Kit



AT3 Ambidextrous Safety Selector


Affordable Ambidextrous AR-15 Lower Receiver

Making the AR-15 friendly for left-handed shooters used to be a tall order.  Thankfully for the southpaws out there, starting a completely ambidextrous lower build has never been easier or more affordable.  This ambidextrous AR-15 lower receiver from Unbranded AR adds a right-side bolt release a a classic forged receiver.  With the addition of a few proprietary parts, you can chamber a round from either side of the gun.

Outside of that, the lower is the same as any other; your favorite parts and accessories will work flawlessly.  Unbranded AR has made sure that this ambidextrous AR-15 lower receiver can accept a wide variety of mil-spec and aftermarket components so you can build this out any way you want.

To make a complete ambi lower receiver, be sure to pick up an ambidextrous magazine catch assembly, and choose from any of the ambidextrous safety selectors we have.  Don’t forget a good trigger and a buffer tube kit!

This lower includes the proprietary components for the right-side bolt release.  These include the bolt release paddle, roll pin, bolt catch spring, and enlarged bolt catch plunger shown.


  • Ambidextrous bolt release (proprietary parts included, assembly required)
  • Manufactured to mil-spec dimensions
  • Precision broached magazine well
  • Compatible with mil-spec components and most aftermarket parts
  • Made in USA


  • Material: Forged 7075 T-6 Aluminum
  • Finish: Type 3 Class 2 Hard Coat Anodizing
  • Weight: 9oz


Receiver Material7075-T6 Aluminum
Firearm TypeLower Receiver
Weight9 ounces

Have Questions About this Product?

Customer Reviews

Based on 4 reviews
Nice Ambi Lower for a Reasonable Price

Fit together in my build like it was supposed to. No problem with Geisele trigger, or Armaspec ambi short-throw safety selector. I would have preferred more flare to the magwell, but otherwise I'm very happy with this lower - especially for the price.

Thanks for sharing your feedback! We're glad you're satisfied with your purchase.

Quality and price!

I have purchased stripped lowers from lots of different manufacturers. I would put this in the top 3 for quality and hands down number 1 for price. I even took a chance on a half dozen blemished lowers that were dirt cheap cost wise but I can't find anything even blemished on any of them. This is my go to from here on out, assuming they keep it up.

Thanks for sharing your feedback! We're glad you're satisfied with your purchase.

evan lessuk
good product

It does exactly what it is designed to do.

Thanks for sharing your feedback! We're glad you're satisfied with your purchase.

Awesome lower

I am ambidextrous. So I can easily transition from right ro left. I have a spikes ambi lower I love. Just the high cost of those has put me off on buying more of them. As for these lower's all I can say is unbranded ar did an awesome job. All the same features I love at a fraction of the cost. I bought 2 of these to replace standard lowers I own.

Only down side to these that I have found. Is on the ambi bolt release when using kns anti rotating pins is the paddle makes contact with the bar, and doesn't allow the bolt to drop. Minor Drexel work to releave a small area on the paddle will take care of this. Other than that flawless.

Thanks for sharing your feedback! We're glad you're satisfied with your purchase.