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Stag Arms AR-15 A3 Flattop Upper Receiver Up to $10.00 Off w/ Free Shipping — 3 models

Stag Arms AR-15 A3 Flattop Upper Receiver, Stripped, Direct Impingement, Type 3 Hard Coat Anodized, Left Hand, Black, STAG310264
Stag Arms AR-15 A3 Flattop Upper Receiver Assembly, Direct Impingement, Type 3 Hard Coat Anodized, Right Hand, Black, STAG300412
Stag Arms AR-15 A3 Flattop Upper Receiver Assembly, Direct Impingement, Left Hand, Cerakote, FDE, STAG310864
Stag Arms AR-15 A3 Flattop Upper Receiver, Stripped, Direct Impingement, Type 3 Hard Coat Anodized, Left Hand, Black, STAG310264
Stag Arms AR-15 A3 Flattop Upper Receiver Assembly, Direct Impingement, Left Hand, Cerakote, FDE, STAG310864
Stag Arms AR-15 A3 Flattop Upper Receiver, Stripped, Direct Impingement, Type 3 Hard Coat Anodized, Left Hand, Black, STAG310264
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Stag Arms AR-15 A3 Flattop Upper Receiver, Stripped, Direct Impingement, Type 3 Hard Coat Anodized, Left Hand, Black, STAG310264
Stag Arms AR-15 A3 Flattop Upper Receiver Assembly, Direct Impingement, Type 3 Hard Coat Anodized, Right Hand, Black, STAG300412
2 of 5 images
Stag Arms AR-15 A3 Flattop Upper Receiver Assembly, Direct Impingement, Type 3 Hard Coat Anodized, Right Hand, Black, STAG300412
Stag Arms AR-15 A3 Flattop Upper Receiver Assembly, Direct Impingement, Left Hand, Cerakote, FDE, STAG310864
3 of 5 images
Stag Arms AR-15 A3 Flattop Upper Receiver Assembly, Direct Impingement, Left Hand, Cerakote, FDE, STAG310864
Stag Arms AR-15 A3 Flattop Upper Receiver, Stripped, Direct Impingement, Type 3 Hard Coat Anodized, Left Hand, Black, STAG310264
4 of 5 images
Stag Arms AR-15 A3 Flattop Upper Receiver, Stripped, Direct Impingement, Type 3 Hard Coat Anodized, Left Hand, Black, STAG310264
Stag Arms AR-15 A3 Flattop Upper Receiver Assembly, Direct Impingement, Left Hand, Cerakote, FDE, STAG310864
5 of 5 images
Stag Arms AR-15 A3 Flattop Upper Receiver Assembly, Direct Impingement, Left Hand, Cerakote, FDE, STAG310864

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Questions & Answers
What makes this a 300 BLK upper? Expert Answer

There is nothing about this Stag Arms 15 A3 upper receiver that makes it specific to 300 BLK. There is a typo and the product page is being updated.

by Hunter, Gear Expert, August 18, 2022
will it work with a left-hand .223 bcg Expert Answer

Yes. The Stag Arms 15 A3 .300 AAC Blackout Upper Receiver Assembly is designed to be paired with a left handed BCG.

by Ethan, Gear Expert, January 20, 2022
View All Q&A You Have a Question? Ask!
Customer Reviews
Helpful Positive Review
Coincidence? by Simonsay629, Verified Owner, August 13, 2021
Arrived on my front door step on National Left Hand Day. Today!!! Coincidence? Cant wait to put this together and test. Finally. No more burnt biceps. Looks like well built, good quality. Fast shipping.
3/4 found this helpful
Helpful Positive Review
Stag Arms Left Hand Upper by Max, Verified Owner, November 16, 2021
My first experience with Stag. The upper is well made and no complaints. I do see that I will have to modify/shorten the ejection port cover rod to make the upper work with a rail that has anti-rotation that extends on the upper’s sides. Other than t...
Read More...
2/2 found this helpful
Helpful Positive Review
Best and really only option for left handed ARs by Bryan Verduzco, Verified Owner, July 8, 2020
this is my second stag left handed upper that I have purchased. Both have been well made and high quality, this one is no exception. I was able to put my rifle together with no issues and this thing is holding up just fine.
10/10 found this helpful
Most Recent Reviews
Stag upper reciever by Ncoutlaw, Verified Owner, November 6, 2025
Part is top notch. great quality and attention to detail.
Most Recent Reviews
Too much of a hassle by Olowrin, Verified Owner, November 18, 2023
I'm left handed. If you buy this, you will need to also have left handed everything. The BCG must be a left handed one (only made by Stag). The free-float rail also will not fit this since the ejection port opens from the top. I couldn't get it to fi...
Read More...
0/4 found this helpful
Most Recent Reviews
Upper receiver by Rob, Verified Owner, April 22, 2025
All I can say is that it looks great nice job keep up the great job
Read All 12 Reviews
3 Models Available
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made-in-usa-flag Made in USA

Help support American manufacturing! Marked models of this product have gone through rigorous review and been certified by the manufacturer as Made in the USA.

Product Info for Stag Arms AR-15 A3 Flattop Upper Receiver

The A3 upper receiver assembly is made to mil-spec standards and includes a picatinny rail on the top, dust cover, and installed forward assist.image

WARNING: California`s Proposition 65

Specifications for Stag Arms AR-15 A3 Flattop Upper Receiver:

Manufacturer: Stag Arms
Fabric/Material: Aluminum
Gun Make: AR Platform
Gun Model: AR-15
Condition: New
Country of Origin: USA

Features of Stag Arms 15 A3 Upper Receiver Assembly:

  • Pivot/Takedown Pin Size: Small pin - .250"
  • Material: Forged and mil-spec with type 3 hard coat anodizing and a picatinny rail on top

Package Contents:

  • Stag Arms AR-15 A3 Flattop Upper Receiver

What firearm models does the manufacturer say Stag Arms AR-15 A3 Flattop Upper Receiver is compatible with?

The manufacturer suggests that Stag Arms AR-15 A3 Flattop Upper Receiver is compatible with AR-15

Stag Arms AR-15 A3 Flattop Upper Receiver Orderable Models

List of Orderable Models

  • Stag Arms AR-15 A3 Flattop Upper Receiver, Stripped, Direct Impingement, Type 3 Hard Coat Anodized, Left Hand, Black, STAG310264 , MPN: STAG310264 , UPC: 840213903299 , Code: 2PS-UPR-AR15A3FURA-STAG310264
  • Stag Arms AR-15 A3 Flattop Upper Receiver Assembly, Direct Impingement, Type 3 Hard Coat Anodized, Right Hand, Black, STAG300412 , MPN: STAG300412 , UPC: 811546026719 , Code: 2PS-UPR-AR15A3FURA-STAG300412
  • Stag Arms AR-15 A3 Flattop Upper Receiver Assembly, Direct Impingement, Left Hand, Cerakote, FDE, STAG310864 , MPN: STAG310864 , UPC: 840213903336 , Code: 2PS-UPR-AR15A3FURA-STAG310864

Stag Arms AR-15 A3 Flattop Upper Receiver Unavailable & Discontinued Models

List of Unorderable Models

  • USED Stag Arms AR-15 A3 Flattop Upper Receiver, Assembly, Direct Impingement, Type 3 Hard Coat Anodized, Left Hand, Black, STAG310412, EDEMO7, Used, Condition Fair , MPN: STAG310412-EDEMO7 , Code: 2PS-UPR-AR15A3FURA-STAG310412-EDEMO7
  • USED Stag Arms AR-15 A3 Flattop Upper Receiver Assembly, .250 Small Pin, Left Hand, Type 3 Hard Coat Anodized, Picatinny Rail, Black, STAG310412, EDEMO6, Condition Fair, Used , MPN: STAG310412-EDEMO6 , Code: 2PS-UPR-AR15A3FURA-STAG310412-EDEMO-US-D
  • USED Stag Arms AR-15 A3 Flattop Upper Receiver, Assembly, Direct Impingement, Type 3 Hard Coat Anodized, Left Hand, Black, STAG310412, EDEMO9, Condition Fair, Other , MPN: STAG310412-EDEMO9 , Code: 2PS-UPR-AR15A3FURA-STAG310412-EDEMO-OT-D
  • USED Stag Arms AR-15 A3 Flattop Upper Receiver, Assembly, Direct Impingement, Type 3 Hard Coat Anodized, Left Hand, Black, STAG310412, EDEMO8, Used, Condition Fair , MPN: STAG310412-EDEMO8 , Code: 2PS-UPR-AR15A3FURA-STAG310412-EDEMO8
  • Stag Arms AR-15 A3 Flattop Upper Receiver, Assembly, Direct Impingement, Type 3 Hard Coat Anodized, Left Hand, Black, STAG310412 , MPN: STAG310412 , UPC: 811546026955 , Code: 2PS-UPR-AR15A3FURA-STAG310412
  • Stag Arms AR-15 A3 Flattop Upper Receiver Assembly, Direct Impingement, Right Hand, Cerakote, FDE, STAG300864 , MPN: STAG300864 , UPC: 840213903329 , Code: 2PS-UPR-AR15A3FURA-STAG300864
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