AT3™ Pro-Builder™ AR-15 Lower Parts Kit - No Grip or Trigger Assembly
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- 90-day no-hassle returns policy
- Backed by the AT3 Lifetime Warranty! what it covers
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Product description
Perfect Lower Parts Kit for the Premium Builds
This quality lower parts kit excludes the two most commonly upgraded components – the grip and the trigger assembly (fire control group).
This is the perfect kit for premium builds that include premium triggers like the AT3 Tactical 2-Stage Trigger. The kit contains quality, mil-spec parts and provides you with the flexibility to spend money on the parts you want – and none of the extras that will sit in your toolbox.
New Color Options!
We’ve added the option to get a Pro-Builder kit with all the parts you’ll see outside your gun in matching Cerakote! We’ve included a handy guide so you can make sure you’re getting the right color for your build. Naturally, these match with all of AT3’s other Cerakote AR parts.
Cerakote Finishes
- Flat Dark Earth: H-267 Magpul® Flat Dark Earth
- OD Green: H-232 Magpul® OD Green
- Pink: H-224 SIG™ Pink
- Red: H-167 USMC Red
- Blue: H-171 NRA Blue
- Burnt Bronze: H-148 Burnt Bronze
- Tungsten: H-237 Tungsten
- Titanium: H-170 Titanium
American Made Quality
- All parts meet or exceed military specifications (Mil Spec)
- Components are 100% Made in the USA
- Quality packaging keeps components protected and organized
- Backed by the AT3 Lifetime Warranty
This Kit Includes:
- Bolt catch
- Bolt catch plunger
- Bolt catch roll pin
- Bolt catch spring
- Buffer retainer
- Buffer retainer spring
- Magazine catch
- Magazine catch button
- Magazine catch spring
- Pivot pin
- Pivot pin detent
- Pivot pin detent spring
- Selector
- Selector detent
- Selector detent spring
- Takedown pin
- Takedown pin detent
- Takedown pin detent spring
- Pistol grip screw and lock washer
- Detailed parts diagram included for quick and easy part identification
All 9 options on this page
- AT3™ Pro-Builder™ AR-15 Lower Parts Kit - No Grip or Trigger Assembly - Color: Black SKU LPK-PROBUILD-1 · UPC 5060748421746
- AT3™ Pro-Builder™ AR-15 Lower Parts Kit - No Grip or Trigger Assembly - Color: Flat Dark Earth SKU LPK-PROBUILD-FDE · UPC 5060748422828
- AT3™ Pro-Builder™ AR-15 Lower Parts Kit - No Grip or Trigger Assembly - Color: OD Green SKU LPK-PROBUILD-ODG · UPC 5060748422835
- AT3™ Pro-Builder™ AR-15 Lower Parts Kit - No Grip or Trigger Assembly - Color: Pink SKU LPK-PROBUILD-PNK · UPC 5060748422842
- AT3™ Pro-Builder™ AR-15 Lower Parts Kit - No Grip or Trigger Assembly - Color: Red SKU LPK-PROBUILD-RED · UPC 5060748422859
- AT3™ Pro-Builder™ AR-15 Lower Parts Kit - No Grip or Trigger Assembly - Color: Blue SKU LPK-PROBUILD-BLU · UPC 5060748422811
- AT3™ Pro-Builder™ AR-15 Lower Parts Kit - No Grip or Trigger Assembly - Color: Burnt Bronze SKU LPK-PROBUILD-BB · UPC 5060748422804
- AT3™ Pro-Builder™ AR-15 Lower Parts Kit - No Grip or Trigger Assembly - Color: Tungsten SKU LPK-PROBUILD-TG · UPC 5060748422866
- AT3™ Pro-Builder™ AR-15 Lower Parts Kit - No Grip or Trigger Assembly - Color: Titanium SKU LPK-PROBUILD-TI · UPC 5060748422873
Customer reviews 130
Verified buyer Questions & Answers 3
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I’m looking for the SKU: LPK-PROBUILD-FDE builders kit that would also include AT32 stage nickel boron trigger. Any chance you would have this available?
Mike Nahorny · May 7, 2026AT3 Support Team — While we don't offer a pre-packaged kit with that specific SKU, you can easily create this setup by adding the AT3 2-Stage Nickel Boron Trigger to your cart alongside the Pro-Builder Lower Parts Kit.
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SKU: LPK-PROBUILD-1 Hello, I wanted to get some size information from this kit, specifically for the Pistols grip Screw and lock washer.
Christian · Jun 10, 2025AT3 Support Team — The pistol grip screw and lock washer in the LPK-PROBUILD-1 are standard AR-15 Mil-Spec size (#8-32 thread).
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Is your AT3 Black “Pro Builder” lower parts kits Cerakote or manganese phosphate?
Butch · May 22, 2025AT3 Support Team — The AT3 Pro-Builder AR-15 Lower Parts Kit is primarily Cerakote finished
Warranty & returns
Backed by the AT3 Lifetime Warranty!
All AT3 Tactical Brand Products carry a lifetime warranty against manufacturer’s defects.
This includes AT3 Red Dot Sights, Handguards, Iron Sights, and any other product that carries the “AT3 Tactical” or “AT3™” name. For other brands (ex. Magpul or Troy), please refer to the manufacturer’s warranty policy.
In the event that your AT3™ product becomes unusable, we will repair or replace the product at no charge to you.
If we cannot repair your product, we will replace it with a product in perfect working order of equal or better physical condition. The warranty is fully transferable, but we may require information about the original purchase to validate the authenticity of the product.
If your product is in need of warranty service, please contact AT3 Tactical to start the process
Our contact info is available here. To expedite processing, please provide your order information and description of the defect.
Please note: The AT3 Lifetime Warranty does not cover loss, theft, intentional damage or cosmetic damage that doesn’t affect the performance of the product.
90-day no-hassle returns
The AT3 Tactical store has a 90 day no-hassle return policy for products in good condition. You can view the full details of our return policy here.
If you encounter an issue or defect with a product after 90 days of your purchase, you can refer to the manufacturer for a warranty claim. Their policies are below.
