AR-45 Complete Upper Receiver Conversion Kit (BB)



Our Macon Armory AR45 complete upper receiver conversion kit with blowback upper is based on the Colt pattern and provides all you need to convert your existing AR lower into an AR45. Our barrels are black nitride coated and hand-crafted with a 1:16 twist and 5/8 x 24 muzzle thread using 4140 Chrome Molybdenum steel, providing both accuracy, durability and versatility.


AR45 BB conversion kit includes:

  • Barreled upper with bolt
  • MLok free float forearm
  • 11 oz Heavy buffer
  • Magazine well adapter
  • Magazine loader
  • Two magazines
  • A2 muzzle device

It is the customer’s responsibility to be aware of all applicable laws and regulations regarding purchase and ownership of upper receivers with a barrel length of less than 16″. Customers in NY, CA, CT, NJ, MA, MD, and CO will automatically have kits adjusted to include 10 round magazines.

Additional information

Barrel length

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Macon Armory

1 review for AR-45 Complete Upper Receiver Conversion Kit (BB)

  1. Barry (verified owner)

    I bought this rig in 2018. I had one problem with the extractor and Rudy sent me a new BCG with no hassle. He asked questions and I sent pics. Absolutely the best products and terrific customer service. So good that I bought a second kit. Thanks Macon Armory!

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