Lower Parts Kit for AR-15
From complete kits to individual pieces, AT3 has the lower parts you need to build your ultimate AR-15.
We provide high-quality lower receiver parts kit, safety selector, and mag release. READ MORE
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- Lower Receiver Parts - AT3 Tactical (49)
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AT3™
AT3™ FU-BAG™ AR-15 Lost Parts Kit – Springs, Detents, Replacement Components
Made an "Oops" with your New Build? You Detent-Launchin', Spring-Losin' Fool, you. We've all been there. Whether it's rolling the dice on that bargain bin LPK in your local...2 Options -
AT3™
AT3™ Castle Nut for AR-15 Buffer Tubes – 10 Colors Available
Secure Your AR15 Buffer Assembly with a Steel Castle Nut This steel castle nut is an essential piece of an AR15 buffer tube/stock assembly. With standard cuts for use with...10 Options -
Armaspec SFT45/90 Ambi AR 15 Safety Selector – ARM113
Armaspec 45 and 90 Degree Ambi Safety The Armaspec SFT45/90 allows you to modify your AR-15 safety exactly how you like it. This AR-15 safety upgrade features a double-sided steel...6 Options -
CMMG .308 Lower Receiver Parts Kit
All the Parts You Need to Get Started on Your Next Mk3 Build Combine this kit with a buttstock kit to complete your lower group. Compatible with CMMG Mk3 Lowers... -
AT3™
AT3™ Mil-Spec AR-15 Pivot Pin/Takedown Pin Detent Springs – Set of 2
AT3™ Mil-Spec AR-15 Pivot Pin/Takedown Pin Detent Springs - Set of Two All AT3 Tactical lower receiver parts meet or exceed Mil Spec. These parts are guaranteed to fit and... -
AT3™
AT3™ MOTHERFU-BAG™ – The BIG AR-15 Lost Parts Kit – Springs, Detents, Wear Parts,...
Launch a detent? Snap a spring? Don't get mad, just fix it with this AR-15 Lost Parts Kit! Alright, so y'all seem to like the FU-BAG. Like a lot. Which... -
AT3™
AT3™ Mil-Spec AR-15 Pivot Pin/Takedown Pin Detents – 2 or 10 Piece Set
AT3™ Mil-Spec AR-15 Pivot Pin/Takedown Pin Detents - 2 or 10 Piece Set All AT3 Tactical lower receiver parts meet or exceed Mil Spec. These parts are guaranteed to fit...2 Options -
NEW
Magpul MOE Enhanced AR-15 Trigger Guard
Transform Flat Mil-Spec Dimensions into Tactile Ergonomic Perfection The MOE Enhanced trigger guard overhaul ushers forgiving glove integration and positive control to the overlooked lower receiver component. Ditch the awkward...3 Options3 Options3 Options -
AT3™
AT3 Tactical AR-15 Magazine Catch and Button Assembly
AR-15 Magazine Catch with Button and Spring Whether you're finishing a build or replacing stock parts, your AR-15 is going to need reliable magazine retention. This mil-spec assembly includes the...10 Options -
AT3™RECOMMENDED
AT3™ Pro-Builder™ AR-15 Lower Parts Kit – No Grip or Trigger Assembly
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)....10 Options -
AT3™
AT3 Tactical AR-15 Bolt Catch Assembly with Spring, Plunger, and Roll Pin
Mil-Spec AR-15 Bolt Catch with Hardware The AT3 AR-15 Bolt Catch Assembly has everything you need to upgrade or replace an existing bolt catch on your AR-15 lower. You get...10 Options -
AT3™
AT3 Tactical AR-15 Takedown and Pivot Pin Assembly
AR-15 Takedown and Pivot Pins with Springs and Detents If you're completing an AR-15 lower, you won't get far without a good set of takedown and pivot pins. These mil-spec...10 Options -
Strike Industries AR-15 Enhanced Takedown and Pivot Pins
Strike Industries Extended Takedown and Pivot Pins Upgrade your AR with Strike Industries' Extended Takedown and Pivot Pins, available in black, chrome, or gold finishes. Perfect for shooters seeking a...3 Options3 Options3 Options -
Strike Industries AR-15 SHIFT Takedown and Pivot Pins
Strike Industries AR-15 SHIFT Takedown and Pivot Pins Effortlessly maintain your AR15 with Strike Industries' Shift Pins. Featuring an extended grip surface and Quick Detach mechanisms, these pins simplify disassembly...3 Options3 Options3 Options -
Strike Industries Pistol Grip Plug Tool Holder Insert
Handy Tool Hideaway - The Strike Pistol Grip Tool Holder Transform your grip into a discreet tool caddy with the Strike Pistol Grip Plug Tool Holder Insert. This nifty drop-in... -
Strike Industries Picatinny Stock Adapter for Bufferless AR-15
Versatile Picatinny Stock Adapter The Strike AR Picatinny Stock Adapter opens up a new world of customization for your AR platform. Easily mount folding stocks, stabilizers, and other accessories thanks...3 Options3 Options3 Options -
Strike Industries HEX 60-90 Degree Selector Switch for AR-15
Your Choice - Strike Industries HEX 60/90° Selector Switch Customization is key with the Strike Industries HEX 60/90° Ambidextrous Selector Switch for AR-15s. This versatile upgrade lets you choose between... -
Strike Industries Modular Bolt Catch for AR-15
Strike Industries Modular AR Bolt Catch This modular bolt catch lets you easily swap between 4 different button styles - standard, oversized, left extended, and right extended. No need to... -
Strike Industries AR MAGSTOP Fixed Magazine Converter
Legally Store Your AR with This Cost-Effective Solution The Strike Industries AR MAGSTOP provides a simple way to configure your AR-15 or AR-10 for legal fixed magazine storage per certain... -
Strike Industries AR-10 Enhanced Lower Receiver Parts Kit
Elevate Your Build with the Strike AR-10 Enhanced Lower Parts Kit Upgrade your AR-10 lower receiver with the Strike Industries Enhanced Lower Receiver Parts kit, featuring essential components for a... -
Strike Industries AR-10 SHIFT Takedown and Pivot Pins
Strike Industries Shift Pins for AR-10/LR-308 These pins feature an extended grip surface for easy disassembly, eliminating the need for a pin punch. Additionally, the Quick Detach mechanism removes the...3 Options3 Options3 Options -
AT3™
AT3™ Ambidextrous AR15 Safety Selector – 10 Colors Available
A Quick Upgrade to Any AR-style Rifle The AT3 AR-15 Ambidextrous Safety Selector replaces your existing selector all allows for enhanced safety control for both right- and left-handed shooters. This...10 Options -
AT3™
AT3™ Mil-Spec AR-15 Buffer Retainer Spring
Mil-Spec AR-15 Buffer Retainer Spring All AT3 Tactical lower receiver parts meet or exceed Mil Spec. These parts are guaranteed to fit and function in your AR buffer assembly and... -
Armaspec Anti-Walk Trigger and Hammer Pins
Perfect for Drop-In Triggers and Preserving Your Lower Armaspec Stainless Steel Anti-Walk pins are standard .154 sized pins for milspec lowers. These pins are designed to keep your hammer/trigger pins...
Other Lower Receiver Components for AR 15:
AR 15 Buffer Tube Parts (Receiver Extension)
AR-15 Triggers
Buttstocks
Lower Parts Kit for AR-15
Magazines & Parts
Pistol Grips
AR-15 Trigger Guards