ENJOY FAST SHIPPING! SHIPS NEXT BUSINESS DAY!

phone: 888-310-0284
36 of 55 Items
  • Sale
    Mil-Spec AR15 Lower Parts Kit (w/ Hammer and Trigger)

    Mil-Spec AR15 Lower Parts Kit (w/ Hammer and Trigger)

    This LPK offers the parts needed to finish your lower, and for a fraction of the cost of a "retail" bought assembly. This lower parts kit comes with all the internal parts needed to finish your lower, from the pivot pin to the trigger. With this kit...

    Was: $46.79
    Now: $38.99
  • Adjustable Carbine Stock & Buffer Tube Assembly Adjustable Carbine Stock & Buffer Tube Assembly Adjustable Carbine Stock & Buffer Tube Assembly Adjustable Carbine Stock & Buffer Tube Assembly

    Adjustable Carbine Stock & Buffer Tube Assembly

    This butt stock kit includes both an adjustable carbine stock and buffer tube assembly. The adjustable carbine stock is constructed from a durable polymer composite and is designed for quick adjustment. Additionally, this carbine butt stock offers three...

    $29.99
  • Sale
    ar-15-buffer-tube-assembly-mil-spec-1

    Mil-spec AR-15 Buffer Tube Assembly

    The AR-15 Mil-Spec Buffer Tube Assembly is made out of durable 6061-T aluminum, making this product very lightweight. The 3-ounce buffer and carbine coated spring ensure a smooth and reliable operation. The mil-spec six position receiver extension allows...

    Was: $35.99
    Now: $29.99
  • Sale
    AR15 LPK - Missing Parts Kit by KAK

    AR15 LPK - Missing Parts Kit

    The AR15 Missing Parts Kit is perfect for any lost parts, replacement parts, or for your next custom build. What's Included? Buffer retainer (1) Bolt catch spring (2) Bolt catch detent (1) Selector detent (2) Disconnector spring (2) Buffer retainer...

    Was: $11.99
    Now: $9.99
  • Sale
    ar-15-butt-stock-mil-spec-1

    Mil-spec AR-15 Butt Stock

    The AR-15 Mil-Spec Butt Stock is a heavy-duty six-position collapsible stock with built in sling swivel, composed out of high quality reinforced plastic composite. Additional Features: Mil-spec dimensions (commercial variant) Can accomodate six-position...

    Was: $16.79
    Now: $13.99
  • Magpul® MOE® Carbine Stock & Buffer Tube Assembly Magpul® MOE® Carbine Stock & Buffer Tube Assembly 2 Magpul® MOE® Carbine Stock & Buffer Tube Assembly 3 Magpul® MOE® Carbine Stock & Buffer Tube Assembly 4 Magpul® MOE® Carbine Stock & Buffer Tube Assembly 5

    Magpul® MOE® Carbine Stock & Buffer Tube Assembly

    Get all the pieces you need to finish off the shoulder end of your AR in one handy little package. This bundle we've created gets you our buffer tube assembly, but that's not all. The bonus is that we've included a Magpul® MOE® Carbine Stock...

    $59.99
  • Sale
    LR-308/AR-10 Lower Parts Kit (w/ Hammer and Trigger)

    LR-308/AR-10 Lower Parts Kit (w/ Hammer and Trigger)

    We strive to provide the most accurate photographs of our product whenever possible. Due to availability limitations and supply chain constraints, slight variations of the trigger and hammer finsh (stainless or black) may occur.  If you're looking...

    Was: $76.79
    Now: $63.99
  • JMT Single Stage Drop-In 3.5-4 Ib Trigger - Saber JMT Single Stage Drop-In 3.5-4 Ib Trigger - Saber 2 JMT Single Stage Drop-In 3.5-4 Ib Trigger - Saber 3 JMT Single Stage Drop-In 3.5-4 Ib Trigger - Saber 4

    JMT Single Stage Drop-In 3.5-4 Ib Trigger - Saber

    If you're wanting a simple and effective upgrade to your AR to get you into that better-than-mil-spec territory with your trigger, then stop here and read this. You need to check out the Saber. It's JMT's Single Stage Drop-In 3.5-4 lb Trigger, and it'll...

    $99.99
  • Sale
    AR15 LPK - Basic Build Kit

    AR15 LPK - Basic Build Kit

    This AR15 Basic Lower Parts Kit includes all of the basic necessities needed for your own custom build. Most importantly what comes with this kit are the following, a bolt catch kit, magazine catch kit, takedown pin & detent & spring, pivot pin...

    Was: $32.39
    Now: $26.99
  • Sale
    AR15 Ergonomic Pistol Grip by UTG®

    AR15 Ergonomic Pistol Grip by UTG®

    The UTG® AR15 Ergonomic Pistol Grip features a non-slip texture, palm swell, and thumb rest for maximum comfort and stability. The grip angle offers easy accessibility to the trigger along with increasing shooting accuracy for optimal performance. In...

    Was: $13.19
    Now: $10.99
  • Sale
    MOE® Enhanced AR15/M4 Polymer Trigger Guard by Magpul® MOE® Enhanced AR15/M4 Polymer Trigger Guard by Magpul® MOE® Enhanced AR15/M4 Polymer Trigger Guard by Magpul®

    Magpul® MOE® Enhanced AR15/M4 Polymer Trigger Guard

    Stop installing that boring mil-spec trigger guard on every AR you build. The Magpul® MOE® Enhanced AR15/M4 Polymer Trigger Guard is miles ahead of the mil-spec stuff. Why? For starters, it's extremely ergonomic and gives your trigger finger a...

    Was: $10.79
    Now: $8.99
  • Sure Grip for AR-15/M-16 by Ergo Grip Sure Grip for AR-15/M-16 by Ergo Grip

    Sure Grip for AR-15/M-16 by Ergo Grip

    If you frequently use your AR for long durations, then comfort is key. You need to remove the potential for fatigue in your grip hand. With that in mind, Ergo Grip gives your their Sure Grip for AR-15/M-16. First, it's been contoured and shaped for max...

    $24.99
  • RA LE145 Tactical Drop-In Trigger RA LE145 Tactical Drop-In Trigger

    RA LE145 Tactical Drop-In Trigger

    If you're the operator, LEO, or hunter that needs one of the most upgraded and dependable triggers available, the LE145 Tactical Trigger from Rise Armament should be your top choice. This drop-in, single-stage trigger maintains a slightly more robust 4...

    MSRP: $199.00
    $159.00
  • Tactical Deluxe SureGrip for AR-15/M-16 by Ergo Grip

    Tactical Deluxe SureGrip for AR-15/M-16 by Ergo Grip

    If you're like us, you find the mil-spec A2 grip that came standard on your AR uncomfortable. Its hard plastic never really gets any more inviting to your hand, and its angle and texture don't stop your from getting fatigue, especially after periods of...

    $39.99
  • ACT Advanced Combat Trigger by ALG Defense

    ACT Advanced Combat Trigger by ALG Defense

    Got an preference for AR builds reminiscent of those from a previous era? We do too. But like us, you're probably just not a fan of the mil-spec trigger. It's gritty and has a rough pull, and it generally feels like crap. But there's a way to keep that...

    $89.99
  • Enhanced Lower Parts Kit by Strike Industries

    Enhanced Lower Parts Kit by Strike Industries

    If your .223 or 5.56mm AR-15's lower parts kit is worn out needs replaced, or if you just want to refresh the controls on your rifle, you need to get the Strike Industries Enhanced Lower Parts Kit. It'll rejuvenate your lower assembly and also has the...

    $104.99
  • Sale
    MOE® Mil-Spec Carbine Stock by Magpul® MOE® Mil-Spec Carbine Stock by Magpul® MOE® Mil-Spec Carbine Stock by Magpul® MOE® Mil-Spec Carbine Stock by Magpul®

    MOE® Mil-Spec Carbine Stock by Magpul®

    There's a reason Magpul is so great at what they do. Their parts are super rugged, they're as tough if not tougher than mil-spec stuff, and they usually weigh less too. The Magpul MOE® Mil-Spec Carbine Stock is no different. It's light, it's tough,...

    Was: $45.59
    Now: $37.99
  • Sale
    MOE+® EPT SBA3 Lower Build KIt

    MOE+® EPT SBA3 Lower Build KIt

    If you're building an AR-15 in pistol configuration, we can help you complete the lower half of your rifle while keeping you legal at the same time. To help with this, we've assembled this MOE+® EPT SBA3 Lower Build Kit. It comes with everything you...

    Was: $263.99
    Now: $219.99
  • AR15 Enhanced Lower Parts Kit by Aero Precision

    AR15 Enhanced Lower Parts Kit by Aero Precision

    For your next AR-15 build, you should start your lower receiver with a quality lower parts kit, so you don't just end up replacing it later. With that in mind, Aero Precision gives you their AR-15 Enhanced Lower Parts Kit to start your build off in a...

    $114.99
  • Spike's Tactical Pro Grip Spike's Tactical Pro Grip-2

    Spike's Tactical Pro Grip

    Replace that uncomfortable mil-spec grip on your AR with the Pro Grip by Spike's Tactical. It's got an ergonomically correct feel, and it's been shaped and contoured to fit your hand's natural grip to make your hand and your AR fit together like they're...

    $24.99
  • M5 .308 Standard Lower Parts Kit by Aero Precision

    M5 .308 Standard Lower Parts Kit by Aero Precision

    If you plan to start an LR-308 build, you're gonna need a good lower parts kit. Aero Precision makes a lower parts kit designed for their M5, which is their own proprietarily designed .308 rifle that can also work with your LR-308 build, provided yours...

    $99.99
  • Sale
    AR15 LPK Pin And Detent Kit by KAK

    AR15 LPK Pin And Detent Kit by KAK

    The KAK Industry AR15 Pin And Detent Lower Parts Kit was manufactured with top of the line materials for the best quality parts. This kit is great for replacement parts, a new build, or having spare parts. This kit comes with a pivot pin, takedown pin,...

    Was: $23.99
    Now: $19.99
  • MOE-K2+® Grip – AR15/M4 by Magpul MOE-K2+® Grip – AR15/M4 by Magpul-2

    Magpul MOE-K2+® Grip – AR15/M4

    The Magpul MOE-K2+ Grip has a strong rubber mold wrapping around the durable polymer body, preventing snags and damage, which allows this grip to outlast in rugged environments. The MOE-K2+ offers a sharp vertical grip angle, naturally placing the...

    $24.95
  • Drop-In Trigger - RA-140 Super Sporting Drop-In Trigger - RA-140 Super Sporting

    Drop-In Trigger - RA-140 Super Sporting

    "Man, I wish I had a kickass trigger for my AR, that didn't cost half what the entire rifle was worth." Ever thought this? Well stop wishing, and check out the RA-140 Super Sporting Trigger Assembly by Rise Armament. Use this step-by-step guide to...

    MSRP: $179.00
    $129.00
  • Aero Precision Enhanced Lower Parts Kit - M5, .308

    Aero Precision Enhanced Lower Parts Kit - M5, .308

    If you're planning an LR-308 build, a good lower parts kit is on your to-buy list. It'd also be nice if your lower parts kit came with a more comfortable grip than the standard A2 grip. Aero Precision makes a lower parts kit designed for their own M5, a ...

    $134.99
  • Sale
    NiB-X Lower Parts Kit, Mod 3 by WMD Guns

    WMD Guns NiB-X Lower Parts Kit, Mod 3

    You know, you can get more out of your AR shooting experience even just by making minor changes to your AR's lower parts kit. This lower parts kit by WMD Guns is mil-spec save for one detail: the trigger, hammer, and disconnector have all been coated in...

    Was: $107.99
    Now: $89.99
  • QMS Quality Mil-Spec Trigger by ALG Defense

    ALG Defense QMS Quality Mil-Spec Trigger

    There are some who prefer their AR platform rifles traditional or built as close to mil-spec as possible. They enjoy replicas of the Colt model 629 or of the old-school M-16, because they want that nostalgia when they shoot. But there's one problem: the...

    $69.99
36 of 55 Items

Finish or upgrade your stripped lower or fabricated 80% lower.

Finished your 80% lower? Grabbed a stripped receiver that you're ready to assemble? We've got you covered with all the AR lower assembly components you need -- or want to upgrade! Check out the mil-spec LPKs we have in stock. They work with all fabricated 80% units and every mil-spec "retail" lower on the market, including the various calibers you might own: 9mm, 5.56, .223, .308, 300 BLK and more.

Quality AR-15 Lower Parts, Triggers, and Kits

The stock AR trigger gets the job done, sure. But you can enjoy better shot placement and a more ergonomic grip with a few easy drop-in upgrades. We've partnered with Rise Armament, JMT, PSA, Hogue, and other top AR parts makers to offer up some of the best upgraded AR triggers and grips available for the AR platform. 

"How do I install my lower parts kit?"

Installing the lower parts kit in your stripped receiver or fabricated 80% lower is relatively easy. Some basic tools are required, which include:

Need help? Here's our detailed lower parts kit install guide!

"What parts do I need to finish my stripped lower?"

You'll need the following parts, which can all be found right on this page or by clicking the links below to filter products by type: 

Not sure what to buy? Here's our complete parts guide to building the AR-15.


DISCLAIMER: If you are new to the world of DIY gun building, you likely have a lot of questions and rightfully so. It’s an area that has a lot of questions that, without the correct answers, could have some serious implications. At GunBuilders.com, we are by no means providing this content on our website to serve as legal advice or legal counsel. We encourage each and every builder to perform their own research around their respective State laws as well as educating themselves on the Federal laws. When performing your own research, please be sure that you are getting your information from a reliable source.

We are a national retailer of individual components and not all products depicted on this website are legal in every state. Shipping of various products found on this website are prohibited to some states (such as California, Connecticut, District of Columbia, Hawaii, New Jersey, New York, Rhode Island, and Washington). The information, pictures, text or products presented on this website are not a representation by us, and should not be understood by you, that any product or completed firearm is legal to assemble or own in your state of residence. We encourage each and every builder to perform their own research about the state and federal laws that apply to them. It is your responsibility to understand the law and we encourage you to consult with an attorney or your local ATF representative.