AR-15 Build Kits and Assemblies
Build Your Next Custom AR-15 with Quality Kits and Complete Assemblies
Find the right lower parts kits, upper receiver assemblies, and even complete rifle kits to make your next build truly your own! AT3 offers discounted bundles for gun builders, from lower parts kits with matching grips and stocks, to complete uppers with a variety of Cerakote finishes. READ MORE
Sort
Filter
List
Grid
-
Magpul MOE M-LOK Furniture Kit – Stock, Carbine Handguard & Grip for AR 15
Customize the look and feel of your AR with a Magpul MOE Furniture Kit. Save 15% vs purchasing the parts individually, plus free shipping. This furniture set contains 3 easy-to-install...24 Options -
New
Real Avid AR-15 Master Bench Block
Magnetic AR-15 Bench Block for Bolt, Upper, Lower, and More The Master Bench Block acts as a second pair of hands when assembling and disassembling your rifle. This tough block... -
New
2A Armament Palouse-Lite 16 Inch M-LOK 5.56 NATO AR-15 Upper Receiver
Cost Effective, Super Lightweight Upper 2A Armament's Palouse-Lite upper saves on weight dramatically compared to other complete uppers, but still has premium components. The pencil weight barrel is a super... -
New
Troy A3 16 Inch Complete 5.56 NATO M-LOK Upper Receiver
Troy Complete Complete Upper with Free Float M-LOK Handguard Troy Industries is known for producing equipment made for the pros - and this complete upper is no different. This complete... -
New
Troy A4 16 Inch Complete 5.56 NATO M-LOK Upper Receiver with Backup Sights
Complete Troy Upper with SOCC Handguard and Backup Iron Sights Duty ready with modern features for the pros, the Troy A4 complete upper gives you all the tools you need... -
New
Rosco Manufacturing 11.5 Inch Sauce Pack – AR-15 Stainless Barrel, BCG, Gas Block &...
11.5 Inch Sauce Pack with Bloodline Nitride AR-15 Barrel The Rosco "Sauce Pack" delivers high quality components for the core of your rifle build. This kit includes a 11.5 inch... -
New
Spike’s Tactical Complete AR-15 Upper Receiver with 16 Inch M4 Profile 5.56 NATO FN...
Complete Upper with M4 Profile Hammer Forged FN Barrel Rugged and ready for duty, this complete upper from Spike's Tactical features a cold hammer forged barrel made by FN, with... -
New
Spike’s Tactical Complete AR-15 Upper Receiver with 16 Inch Midlength 5.56 NATO FN Barrel
Complete Upper with Midlength Hammer Forged FN Barrel Rugged and ready for duty, this complete upper from Spike's Tactical features a cold hammer forged barrel made by FN, with a... -
New
Rosco Manufacturing 10.5 Inch Sauce Pack – AR-15 Stainless Barrel, BCG, Gas Block &...
10.5 Inch Sauce Pack with Bloodline Nitride AR-15 Barrel The Rosco "Sauce Pack" delivers high quality components for the core of your rifle build. This kit includes a 10.5 inch... -
New
Rosco Manufacturing 13.7 Inch Sauce Pack – AR-15 Stainless Barrel, BCG, Gas Block &...
13.7 Inch Sauce Pack with Purebred Stainless AR-15 Barrel The Rosco "Sauce Pack" delivers high quality components for the core of your rifle build. This kit includes a 13.7 inch... -
New
Rosco Manufacturing 12.5 Inch Sauce Pack – AR-15 Stainless Barrel, BCG, Gas Block &...
12.5 Inch Sauce Pack with Bloodline Nitride AR-15 Barrel The Rosco "Sauce Pack" delivers high quality components for the core of your rifle build. This kit includes a 12.5 inch... -
New
BCM MK2 Recoil Mitigation System Mod1 for AR-15
Recoil Reducing AR-15 Buffer Kit Bravo Company's MK2 Recoil Mitigation System effectively reduces recoil with a few changes to key components. This kit uses a longer, 8 position buffer tube,...3 Options -
Magpul CTR Stock Kit | Furniture Kit for AR-15– CTR Stock, MOE+ Grip &...
Transform Your Rifle With The Magpul Premium Furniture Kit Save over 15% vs purchasing the parts individually, plus free shipping. Exclusively from AT3 Tactical This Premium version of our popular,...12 Options -
AT3™Handguard-Fest!
AT3 SPEAR Furniture Kit – AT3 AR 15 M-LOK Handguard, Magpul MOE Stock &...
Accurize and customize your AR with an AT3 Free-Float Rail and matching Magpul furniture! Save by bundling vs purchasing the parts individually, plus free shipping. This furniture set contains 3...24 Options -
UTG Pro Six Position Mil-spec AR 15 Buffer Tube Kit
Complete UTG Buffer Assembly - Add Your Own Stock This receiver extension kit from UTG comes with a buffer tube, buffer spring, 3.0 oz carbine buffer, castle nut, and endplate. ...2 Options -
Magpul MOE SL | AR 15 Stock, Grip & M-LOK Handguard
Stand out from the crowd - Upgrade your AR-15 with the Magpul MOE SL™ Slim Line Furniture Kit Save over 15% vs purchasing the parts individually, plus free shipping. Exclusively...12 Options -
UTG Pro AR-15 Ops Ready S4 Mil-Spec Stock Kit – Buffer Assembly Included
Compact AR-15 Stock Kit for CQB and PDWs The two-piece S4 stock comes with a complete set of all the parts you'll need for finishing off your AR-15's recoil system. ...2 Options -
UTG A2 Fixed AR 15 Rifle Stock Assembly – All Parts Included – Buffer,...
Highly Recommended Rock Solid Fixed Stock - Tough Finish, Easy to Install This is a complete kit that includes a 4.8-ounce buffer, action spring, receiver extension, stock, butt plate, stock... -
UTG PRO 6-Position Mil-spec AR 15 Stock Kit – All Parts Included – Buffer,...
UTG PRO 6-Position Mil-spec Stock Kit - All Parts Included - Buffer, Tube, Springs, & More Proudly Made in USA Polymer Stock Made from Impact Resistant High-strength Material Mil-spec Diameter...2 Options -
AT3™
AT3 AR 15 Lower Build Kit – Magpul Stock and Grip, AT3 Lower Parts...
Finish Off Your New Rifle Lower with an Enhanced Trigger and Matching Magpul Furniture Your AR lower has some of the most critical parts you don't want to skimp on...4 Options -
UTG PRO S3 Mil-Spec AR 15 Buttstock Kit – All Parts Included – Buffer,...
UTG PRO S3 Mil-Spec Buttstock Kit - All Parts Included - Buffer, Tube, Springs, & More Built for Heavy-duty Use with the Tightest Tolerance Controls to Provide the Most Secure...2 Options -
TacFire RK556 Unassembled AR-15 Complete Rifle Kit
Unassembled Rifle Kit with Free-Float Handguard Build a complete AR-15 that can do it all at an excellent price point with Tacfire. This kit ships to your door unassembled, with... -
AT3™
AT3™ FF-ML Complete Rifle AR 15 Upper – .223/5.56 16″ Faxon Firearms Barrel –...
Uncompromising quality meets unbeatable value. The AT3 Tactical FF-ML Complete AR-15 Upper, now with a lightweight Faxon Gunner barrel! AT3 Complete Upper assemblies are Built for Accuracy and Reliability -...16 Options -
AT3™
AT3™ FF-ML 10.5 Inch .300 Blackout Pistol Upper for AR-15 – 12″ M-LOK Free...
Uncompromising quality meets unbeatable value - The AT3 10.5" .300 BLK Pistol Upper with SPEAR M-LOK Handguard AT3 Complete Upper assemblies are Built for Accuracy and Reliability - Guaranteed. Quality...8 Options
Other Other AR-15 Parts & Accessories:
All Other Products
AR 15 Furniture Kits
AR-15 Cleaning Kit and Tools
AR-15 Conversion Kits .22 LR and More
AR-15 Rifle Bipods
AR-15 Slings & Mounts
AR-15 Upper: Complete Upper Assemblies
Rifle Cases for AR-15
AR-15 Build Kits and Assemblies
AT3 Swag
