• Post category:Lower Receivers
  • Post last modified:August 28, 2022
  • Reading time:28 mins read

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If you’re in the market for a new lower parts kit, then you’ve come to the right place. In this blog post, we will be taking a look at some of the best lower parts kits currently available on the market. We’ll be discussing what makes each one of these kits special, and we’ll also provide you with a few tips on how to choose the right kit for your needs. So without further ado, let’s get started!

Best Lower Parts Kit

Top 20 Best AR 15 Lower Parts Kit

#1 COLT – LOWER RECEIVER PARTS KIT

COLT - LOWER RECEIVER PARTS KIT

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The Colt Lower Receiver Parts Kit is a great way to ensure that your AR-15 lower receiver is built with all genuine Colt factory parts. This convenient kit includes all the small parts needed to finish a small-pin AR-15 lower receiver, as well as install the trigger group and pistol grip of your choice. With parts designed to work together from the single-manufacturer source that developed the original AR-15/M16 platform, you can be sure of a tight, consistent fit with minimal fitting required. The Accu-Wedge included in the kit fills the space behind the takedown pin to prevent unwanted movement between the receiver halves, helping your rifle shoot tight, consistent groups. Get this essential kit today and keep your AR running like new.

Pros:
  • Genuine Colt factory parts
  • Convenient kit of all small parts needed to finish a lower receiver and install the trigger group and pistol grip
  • Single-manufacturer source
  • Parts designed to work together with minimal fitting required
  • Accu-Wedge included helps rifle shoot tight, consistent groups
Cons:
  • May require fitting
  • Not compatible with .308 platform rifles
  • Trigger, hammer, disconnector and pistol grip are not included

#2 CMC TRIGGERS – AR-15 LOWER PARTS KIT

CMC TRIGGERS - AR-15 LOWER PARTS KIT

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If you’re looking for a top-quality AR-15 lower parts kit that includes everything you need to complete your lower receiver, without any unnecessary components, then the CMC Triggers AR-15 Lower Parts Kit is the perfect choice for you. This lower parts kit includes all the small parts needed to complete your AR-15 lower receiver, and all parts included meet or exceed military specifications. However, what sets this lower parts kit apart from others on the market is that it does not include a trigger, hammer or associated springs – meaning you can choose the exact components you want for your build, without paying for anything you don’t need. So if you’re looking for a high-quality, customizable lower parts kit that won’t break the bank, the CMC Triggers AR-15 Lower Parts Kit is the ideal choice for you.

Pros:
  • Includes components you need to complete a lower receiver
  • Top-quality construction and materials
  • All parts meet military specifications
  • Affordable price
Cons:
  • Does not include a trigger, hammer or associated springs
  • Lower parts kit may be too basic for some users

#3 GEISSELE AUTOMATICS LLC – AR-15 LOWER PARTS KIT

GEISSELE AUTOMATICS LLC - AR-15 LOWER PARTS KIT

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The Geissele Automatics Llc – AR-15 Lower Parts Kit is a great way to get your lower receiver operational. This kit contains all 17 parts necessary to get your lower receiver operational. Geissele is renowned for superbly designed, meticulously manufactured products, and these parts meet their high standards. The items in the AR-15 Lower Parts Kit are manufactured to “mil-spec” (M16 / M4) dimensions to ensure optimum fit and function in your AR rifle or carbine. There is nothing superfluous in the kit. As a result, you won’t have to spend money on parts you won’t use!

Pros:
  • Geissele is renowned for superbly designed, meticulously manufactured products
  • Contains all 17 parts necessary to get your lower receiver operational
  • Items in the AR-15 Lower Parts Kit are manufactured to “mil-spec” (M16 / M4)
  • All parts of the kit dimension to ensure optimum fit and function
Cons:
  • Does not include the fire control system and pistol grip
  • Assembling the lower receiver may be challenging for those who are new to firearms

#4 CMMG – AR-15 LOWER PARTS KIT

CMMG - AR-15 LOWER PARTS KIT

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Looking to build or rebuild an AR-15 lower receiver? This CMMG Lower Parts Kit is just what you need. It comes with everything you need to get the job done right, including a high-quality trigger, molded-polymer A2 pistol grip, and all the necessary pins, springs, detents and screws. Plus, it’s all conveniently packaged in color-coded bags that make assembly a breeze. So why wait? Get your hands on this great lower parts kit today and get started on your next project!

Pros:
  • Comes with all the internal parts you need to complete or rebuild an AR lower receiver
  • Components are designed to work in coordination with each other for smooth operation
  • Conveniently packaged in color-coded bags that make assembly a breeze
  • Conventional, single-stage trigger pull
Cons:
  • May not fit all AR-15 lower receivers
  • Trigger pull may be too heavy for some shooters
  • Several users have reported poor quality control with some of the components

#5 CRITICAL CAPABILITIES LLC – AR-15 LOWER PARTS KIT

CRITICAL CAPABILITIES LLC - AR-15 LOWER PARTS KIT

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Introducing the AR-15 Lower Parts Kit from Critical Capabilities LLC. This is a high-quality, affordable lower parts kit that is perfect for any AR-15 build. The kit includes all the necessary components to complete your lower, including the ELG trigger. This trigger is precision ground and polished for a smooth, consistent pull. It’s also the perfect foundation for a trigger job, giving you a great starting point for a custom trigger setup. So the AR-15 Lower Parts Kit from Critical Capabilities LLC is a perfect choice. Furthermore, this kit includes all the necessary lower receiver hardware, machined or forged to ensure durability in all weather conditions. The lower parts feature a thick and matte black hard coat anodized finish.

Pros:
  • High-quality and affordable
  • Perfect for AR-15 builds
  • ELG trigger is precision ground and polished
  • Smooth, consistent pull
  • Great foundation for a custom trigger setup
  • Machined and forged parts
Cons:
  • Lower parts kit may be too basic for some customers
  • Anodized finish is occasionally too thick

#6 DOUBLE STAR – AR-15 LOWER PARTS KIT

DOUBLE STAR - AR-15 LOWER PARTS KIT

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Looking for a top-quality AR-15 lower parts kit that won’t let you down? Double Star’s AR-15 Lower Parts Kit is perfect for those who demand the best. This kit is made in the USA from mil-spec heat treated 8620 steel, so you know it’s built to last. The smooth finish on all touchpoints and crisp trigger pull with minimal creep or drag make this an excellent choice for your next lower parts kit. Plus, the metal injected molded parts are more affordable than similar kits on the market. And Double Star’s coiled steel spring pins are easier to install than the standard split roll pins. So why settle for anything less than the best? Get your Double Star AR-15 Lower Parts Kit today!

Pros:
  • Quality American made parts
  • Crisp trigger pull with minimal creep or drag
  • Coiled steel spring pins instead of split roll pins
  • Additional takedown detent and spring included
Cons:
  • Fire control group pins and springs can be difficult to install
  • Kit is expensive compared to other brands

#7 CMMG – 308 AR LOWER PARTS KIT

CMMG - 308 AR LOWER PARTS KIT

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Planing to build or rebuild an AR-style rifle? The CMMG 308 AR Lower Parts Kit has everything you need to get the job done right. High-quality, precision-machined components are designed to work together for smooth operation, and they’re packaged in color-coded bags for easy assembly. The kit includes an A2-style pistol grip, trigger, trigger spring, hammer, disconnector, hammer/trigger retaining pins, hammer spring, bolt stop and screw, selector, selector detent, bolt catch, magazine catch, magazine release button, front pivot pin, rear takedown pin, buffer retainer, triggerguard assembly, and all necessary pins, springs, detents and screws. So whether you’re a first-time builder or a seasoned pro, the CMMG 308 AR Lower Parts Kit has everything you need to create a top-quality rifle.

Pros:
  • Reliable and durable components
  • Color-coded packages for easy assembly
  • A2-style pistol grip
  • Mil-Spec trigger
Cons:
  • Not compatible with all lower barrels
  • Not a full complete set

#8 CMMG – AR-15 LOWER PARTS KIT

CMMG - AR-15 LOWER PARTS KIT

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Looking to build or rebuild an AR-15 lower receiver? The CMMG Lower Parts Gunbuilder’s Kit contains all the internal parts needed to get the job done. This kit comes with high-quality components designed to work together for smooth operation and everything a shooter needs to complete a lower receiver build. The kit includes a takedown pin, receiver pivot pin, takedown pin detent, takedown pin detent spring, hammer and trigger pin, safety selector, selector detent, magazine catch, magazine catch spring, magazine release button, bolt catch, bolt catch plunger, bolt catch spring, bolt catch spring pin, buffer retainer and buffer retainer spring. With everything you need in one convenient kit, the CMMG Lower Parts Gunbuilder’s Kit has you covered.

Pros:
  • The parts are color-coded and organized in related sets for easy assembly
  • High-quality components for smooth operation
  • Includes molded polymer A2 pistol grip and Mil-Spec trigger
  • Everything a shooter needs to complete a lower receiver build
Cons:
  • Kit does not include a trigger, grip, trigger guard
  • Some parts may require fitting
  • May not be compatible with all AR-15 receivers

#9 KE ARMS LLC – AR-15 GI LOWER PARTS KIT

KE ARMS LLC - AR-15 GI LOWER PARTS KIT

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The KE Arms AR-15 Lower Parts Kit has everything you need to turn your bare lower receiver into a functional part of your custom AR-15 or M4 build. All parts are made in the USA and the kit includes an enhanced polymer winter trigger guard, A2 pistol grip, fire control group with black oxide coated hammer spring, magnesium phosphate coated hammer, and trigger spring, spring bolt catch, and disconnector spring. Plus, all the necessary roll pins and set screws for easy installation. Get everything you need to complete your build with the KE Arms AR-15 Lower Parts Kit.

Pros:
  • Made in the USA
  • Enhanced polymer winter trigger guard
  • Roll pin and set screw for easy installation
  • A2 pistol grip constructed of molded glass-filled nylon for durability and optimal strength
  • All parts interact smoothly
Cons:
  • Safety may work intermittently
  • Risk of the hammer jamming

#10 BROWNELLS – AR-15 LOWER PARTS KIT

BROWNELLS - AR-15 LOWER PARTS KIT

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Brownells has the perfect lower parts kit for building or rebuilding your AR-15 rifle! This 5.56 NATO kit is made of all high quality, Made in the USA, Mil-spec parts. Each part is well-made, durable and packaged in color-coded bags for easy installation. This kit is an excellent choice for building or rebuilding an AR-15 rifle. Contains: takedown pin, receiver pivot pin, takedown pin detent, takedown pin detent spring, bolt catch, bolt catch plunger, bolt catch spring pin, bolt catch spring, buffer retainer, buffer retainer spring, magazine catch, magazine catch spring, magazine catch button, trigger guard assembly, trigger guard pivot spring pin, safety selector, selector detent, selector detent spring, grip screw washer, grip screw. Don’t wait any longer, order your Brownells AR-15 Lower Parts Kit today!

Pros:
  • Opportunity for customization
  • A solid, just the basics build kit
  • Best for upgrading common parts right
  • It will save you money in the long run if you upgrade parts
Cons:
  • No ambidextrous safety controls
  • No fire control group or pistol grip included

#11 TRYBE Defense Mil-Spec Complete Lower Parts Kit

TRYBE Defense Mil-Spec Complete Lower Parts Kit

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If you have an AR-15 Lower Receiver and need all the parts to complete your build, check out the Trybe Defense COMPLETE Lower Parts kit. This kit is designed to fit your AR-15 perfectly and includes everything you need: hammer, trigger, bolt catch, buffer retainer, magazine catch, pistol grip, necessary pins and springs, and so on. You will never be disappointed with this product – it’s the perfect way to finish your AR-15 build!

Pros:
  • Reasonable price
  • Compatible and highly reliable components
  • Exact match with the lower part of the AR-15 receiver
  • All necessary parts included
Cons:
  • Some parts may be difficult to install
  • Low on features

#12 Aero Precision AR-15 Lower Parts Kit

Aero Precision AR-15 Lower Parts Kit

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Looking for a versatile and durable lower parts kit for your AR-15? Look no further than Aero Precision’s line of lower parts kits featuring Magpul grips. These kits are available in black and FDE and come with either MOE or MOE SL grip options. With our tried and true mil-spec fire control group, you can rest assured that your AR-15 will be in good hands. So don’t wait any longer, order your Aero Precision lower parts kit today!

Pros:
  • Proper quality and durability
  • All small parts included
  • Aftermarket upgrades are available
  • Compatibility with other MIL-SPEC parts
  • Allows for custom-builds
Cons:
  • Does not include instructions
  • May be difficult to install

#13 RISE Armament Lower Parts Kit

RISE Armament Lower Parts Ki

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If you’re going to upgrade or replace the lower parts of your AR-15, this RISE Armament Lower Parts Kit is an excellent choice. It includes 20 essential pieces to help keep your firearm functioning at its best, plus standard trigger pins and safety. Clear, easy-to-see packaging makes it easy to find what you need and get the job done right. Note that this kit does not include a trigger – perfect for custom builds. Get the parts you need to take your AR-15 to the next level with this RISE Armament Lower Parts Kit.

Pros:
  • 20-piece kit
  • Standard trigger pins and safety
  • Suitable for replacing multiple parts or the entire receiver
  • Good for individual assembly
Cons:
  • Not complete, missing trigger

#14 Aero Precision Enhanced Lower Parts Kit

Aero Precision Enhanced Lower Parts Kit

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The Aero Precision Enhanced Lower Parts Kit is a top-quality lower receivers kit perfect for those looking to build a custom AR15 from the ground up. With Mil-spec dimensions and coatings, it guarantees the highest quality and correct component interface. This upgraded Enhanced Lower Parts Kit also features a Magpul MOE Grip and Aero Precision Billet Trigger Guard for even more durability and performance.

Pros:
  • Mil-spec dimensions and coatings
  • Includes Magpul MOE Grip
  • Has Magpul Billet Trigger Guard
  • The components are corrosion-resistant
Cons:
  • Some users have complained about the quality of the components
  • May not be compatible with certain AR models

#15 CMMG AR-15 Lower Reciever Parts

CMMG AR-15 Lower Reciever Parts

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Looking for a reliable and high-quality AR-15 lower receiver parts kit for your next build? Look no further than the CMMG, Inc AR-15 Lower Receiver Parts Kit. These parts are crafted to meet and exceed mil-spec standards, making them perfect for customizing your AR-15 rifle. The kit includes most of the necessary parts to build up your lower group, except for the commonly upgraded parts. This makes it easier than ever to get a great result with your next build. So don’t settle for less – make sure you have the CMMG, Inc AR-15 Lower Receiver Parts Kit on hand for optimum results.

Pros:
  • Compatible with rifle butt stock kits
  • Perfect for modifying AR-15 rifles
  • Crafted to the highest quality standards
  • Includes most of the necessary parts to build up a lower group
Cons:
  • Fitting may be necessary
  • Assembly can be complicated for beginners

#16 CMC Triggers Complete Lower Receiver Parts Kit

CMC Triggers Complete Lower Receiver Parts Kit

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Going to build or upgrade your AR-15? The CMC Triggers Complete Lower Receiver Parts Kit is perfect for gunsmiths and experienced builders alike. These high-quality, Mil-Spec parts are constructed from steel for improved performance and durability. With all parts meeting or exceeding MIL-SPEC standards, you can be confident in the quality of this lower parts kit. Don’t set for anything less than the best – choose the CMC Triggers Complete Lower Receiver Parts Kit for your next build.

”Pros:”
  • May be difficult to install
  • Insufficient functionality
”Cons:”

    #17 Aero Precision Standard Lower Parts Kit

    Aero Precision Standard Lower Parts Kit

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    Looking to build a custom AR15 from the ground up? Our Aero Precision Standard Lower Parts Kit is just what you need! Mil-spec dimensions and a durable coating ensure the highest quality and correct component interface. Plus, our Aero Precision AR15 Standard Lower Parts Kit is a great value for the money. Don’t settle for anything less than the best – get your lower parts kit from Aero Precision today!

    Pros:
    • Durable coating
    • Standard sizes
    • Compatibility of all components
    • Value for money
    Cons:
    • May not fit all AR15 models
    • Lower quality than some other brands

    #18 Aero Precision AR-15 Lower Parts Kit

    Aero Precision AR-15 Lower Parts Kit

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    Introducing the Aero Precision AR-15 Lower Parts Kit with Magpul Grips! This versatile kit is designed for your needs and is available with MOE and MOE SL Grip Options in Black and FDE. AR15 Lower Parts Kit includes the components needed to assemble an Aero Precision AR15 Gen 2 Lower Receiver or similar mil-spec lower receiver. It features a Magpul MOE SL Grip and Magpul MOE Trigger Guard. This Aero Precision kit has everything you need in a basic lower parts receiver build kit. Stop searching for all the individual parts you need to complete your lower receiver build! The Aero Precision AR-15 Lower Parts Kit with Magpul Grips has everything you need, and at a price that can’t be beaten. Get yours today!

    Pros:
    • Universal set
    • Quality parts
    • MOE SL handle can be installed
    • Mil-spec fire control group
    • Black and FDE colors are available
    Cons:
    • Price is higher than similar kits
    • Some components require fitting

    #19 Aero Precision M4E1 Lower Parts Kit w/Magpul

    Aero Precision M4E1 Lower Parts Kit w/Magpul

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    Looking for a versatile and durable lower parts kit for your M4E1 Lower Receiver? Look no further than the Aero Precision M4E1 Lower Parts Kit w/ Magpul Grip. This kit includes everything you need to assemble your lower receiver, including a Magpul MOE Grip for improved comfort and control. Made from high-quality materials, this lower parts kit is built to last and provides great value for your money. Don’t miss out on this great product – order today!

    Pros:
    • Made from high-quality materials
    • Good value for money
    • Versatile kit
    • Durable and reliable parts
    Cons:
    • May not fit other lower receivers
    • Adjustment is required

    #20 Aero Precision M5 Lower Parts Kit

    Aero Precision M5 Lower Parts Kit

    View on OpticsPlanet

    The Aero Precision M5 Lower Parts Kit is designed to be versatile for your needs. It includes a Magpul MOE Grip and is available with MOE and MOE SL Grip Options in Black and FDE. With our tried and true mil-spec Fire Control Group or save for an upgraded trigger with MINUS FCG offerings, this M5 Lower Parts Kit is perfect for your next build.

    Pros:
    • MOE grip options
    • Mil-spec Fire Control Group
    • Upgraded trigger available
    • Black and FDE colors
    Cons:
    • May not fit all builds
    • Lower quality than some other kits

    FAQ

    What is included in a lower parts kit?

    A Lower Parts Kit typically includes the following:

    • Magazine Catch
    • Trigger Guard
    • Bolt Catch
    • Magazine Release Button
    • Grip Screws
    • Pivot Pin Detents
    • Takedown pin detents
    • Buffer retainer spring
    • Hammer spring
    • Trigger spring

    What tools are needed to install a lower parts kit?

    A Lower Parts Kit installation typically requires a few hand tools, such as a screwdriver, hammer, and pliers. However, it is always best to consult the Lower Parts Kit’s manufacturer instructions to be sure.

    Do you need FFL for the lower parts kit?

    No, you do not need FFL for the lower parts kit. Lower parts kits are not firearms and do not require a license to purchase.

    How much does a lower parts kit weight?

    Lower parts kits typically weigh around 2 pounds.

    Can I use any lower for any caliber?

    It depends on the Lower Parts Kit. Some Lower Parts Kits are specific to a certain caliber, while others are more universal and can be used with multiple calibers. Be sure to read the product description carefully before making your purchase.

    Are all lower receivers the same?

    No, all lower receivers are not the same. There are various types of lowers available on the market, each with its unique features and benefits. When choosing a lower receiver, it is important to consider the type of shooting you plan to do. For example, if you are primarily a target shooter, you may want to consider a precision-machined lower receiver made from a lightweight aluminum alloy. If you are primarily a hunter or outdoorsman, you may want to consider a lower receiver made from a more durable material like steel.

    What is FCG in a lower parts kit?

    The FCG, or Fire Control Group, is the main mechanism that controls the firing of a rifle. It is contained within the Lower Receiver and includes the Trigger, Hammer, and Disconnector.

    Conclusion

    When it comes to Lower Parts Kits, there are a lot of different options on the market. It can be tough to determine which one is the best for your needs. That’s why we’ve put together this comprehensive buyer’s guide to help you make an informed decision. In our guide, we took a look at some of the most popular Lower Parts Kits available and provided you with insights into what makes them so great. We also gave you tips on how to choose the right kit for your needs. Now you know all that these kits have to offer, you can pick one up and start upgrading your AR-15 today!

    Tags: #best lower parts kit / #best ar lower parts kit / #best ar 15 lower parts kit / #best lower parts kit for ar15 / #best ar15 lower parts kit

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