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What is a Lower Parts Kit? ⚙️
📢 A Lower Parts Kit (LPK) is a collection of small mechanical parts that are used to assemble the lower receiver of a firearm. The lower receiver is part of the firearm that houses the trigger group, magazine well, and other essential components.
Features 🔐
| 📍 Includes all necessary small mechanical parts for assembling the lower receiver of a firearm. |
| 📍 Typically includes parts such as the trigger, trigger spring, hammer, hammer spring, disconnector, and various pins and screws. |
| 📍 Compatible with a wide range of firearms. |
| 📍 Made from high-quality materials for durability and reliability. |
| 📍 Easy to install with basic tools and knowledge of firearms assembly. |
Benefits 💣
| 🔵 Saves time and effort compared to sourcing individual parts separately. |
| 🔵Provides a cost-effective way to build or customize a firearm. |
| 🔵 Ensures compatibility between parts and reduces the risk of errors during assembly. |
| 🔵 Helps to improve the performance and functionality of the firearm. |
| 🔵 Allows for customization and personalization of the firearm to suit the user’s needs and preferences. |
What are the parts of a Lower Parts Kit? 🔩
📢 A typical lower parts kit for an AR-15 or similar rifle platform includes a variety of small components necessary for the assembly and function of the lower receiver. 🔎 The specific components may vary depending on the manufacturer and the specific model of the kit, but in general, it typically includes:
- 🔰 Trigger assembly: includes the trigger, trigger spring, hammer, hammer spring, disconnector, and disconnector spring.
- 🔰 Bolt catch assembly: includes the bolt catch, bolt catch plunger, bolt catch roll pin, and bolt catch spring.
- 🔰 Magazine catch assembly: includes the magazine catch, magazine catch spring, and magazine catch button.
- 🔰 Pivot pin assembly: includes the pivot pin, pivot pin detent, and pivot pin detent spring.
- 🔰 Takedown pin assembly: includes the takedown pin, takedown pin detent, and takedown pin detent spring.
- 🔰 Selector assembly: includes the selector, selector detent, and selector detent spring.
- 🔰 Pistol grip assembly: includes the pistol grip, grip screw, and grip screw washer.
- 🔰 Buffer tube assembly: includes the buffer tube, buffer spring, buffer, and buffer tube castle nut.
- 🔰 Other small parts: such as a trigger guard, a receiver extension plate, or a receiver extension lock ring.
Top 20 🚀 AR-15 Lower Parts Kit
1# Colt – Lower Receiver Parts Kit
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 the rifle shoot tight, consistent groups. Get this essential kit today and keep your AR running like new.
2# CMC Triggers – AR-15 Lower Parts Kit
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 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 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 kit that won’t break the bank, the CMC Triggers AR-15 Lower Parts Kit is the ideal choice for you.
3# Geissele Automatics LLC – AR-15 Lower Parts Kit
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!
4# CMMG – AR-15 Lower Parts Kit
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!
5# Critical Capabilities LLC – AR-15 Lower Parts Kit
Introducing the AR-15 Lower Parts Kit from Critical Capabilities LLC. This is a high-quality, affordable 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.
6# Double Star – AR-15 Lower Parts Kit
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. 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!
7# CMMG – 308 Ar Lower Parts Kit
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.
8# CMMG – AR-15 Lower Parts Kit
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.
9# KE ARMS LLC – AR-15 GI Lower Parts Kit
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.
10# Brownells – AR-15 Lower Parts Kit
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!
11# TRYBE Defense Mil-Spec Complete Lower Parts Kit
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!
12# Aero Precision AR-15 Lower Parts Kit
Looking for a versatile and durable lower parts kit for your AR-15? Look no further than Aero Precision’s line featuring Magpul grips. These kits are available in black and FDE and come with either MOE or MOE SL grip options. With the 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!
13# RISE Armament Lower Parts Kit
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.
14# Aero Precision Enhanced Lower Parts Kit
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.
15# CMMG AR-15 Lower Reciever Parts
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.
16# CMC Triggers Complete Lower Receiver Parts Kit
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.
17# Aero Precision Standard Lower Parts Kit
Looking to build a custom AR15 from the ground up? 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, the 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 from Aero Precision today!
18# Aero Precision AR-15 Lower Parts Kit
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!
19# Aero Precision M4E1 Lower Parts Kit w/Magpul
Looking for a versatile and durable 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!
20# Aero Precision M5 Lower Parts Kit
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 the 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.
How To Assemble An AR15 Lower? 💡
🔧 Assembling an AR-15 lower receiver requires some mechanical knowledge and the right tools. 👣 Here are the basic steps:
| 1️⃣ Begin by ensuring that the lower receiver is empty and that there are no rounds or ammunition in the area. |
| 2️⃣ Install the trigger guard onto the lower receiver by aligning it with the holes and pushing the roll pin through using a punch and hammer. |
| 3️⃣ Insert the magazine catch button into the magazine catch and then install the magazine catch assembly onto the lower receiver. Push the roll pin through using a punch and hammer. |
| 4️⃣ Install the bolt catch onto the lower receiver by inserting the spring and plunger into the hole, then aligning the bolt catch with the hole and pushing the roll pin through using a punch and hammer. |
| 5️⃣ Insert the safety selector lever into the lower receiver and then install the safety detent and spring. Slide the pistol grip onto the lower receiver and screw it into place using the provided screw and washer. |
| 6️⃣ Install the trigger, hammer, and disconnector by inserting them into the lower receiver and securing them with the provided pins. |
| 7️⃣ Attach the buffer tube to the lower receiver by screwing it into place using the provided castle nut and end plate. Tighten it to the appropriate torque specification if you have a torque wrench. |
| 8️⃣ Insert the buffer spring and buffer into the buffer tube. |
| 9️⃣ Attach the stock to the buffer tube by sliding it onto the tube and securing it with the provided screw and washer. |
✅ Once you have completed all the steps, you can test the trigger, safety selector, and magazine release to ensure they are working properly.
🎥 Watch the video to see the approximate process:
⚠️ It’s important to follow the manufacturer’s instructions carefully and to double-check your work to ensure everything is assembled correctly and safely.
FAQ 🤔
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 the guide, we took a look at some of the most popular options 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 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
I’m looking for recommendations for a reliable parts kit as I plan to build my first AR instead of purchasing a complete one. Can anyone suggest a good option?
In my experience, CMMG stands out among other brands in terms of quality. Their safety has a positive engagement and smooth travel, while the pivot and takedown pins are extended for easy removal. The machining is expertly done, resulting in pins that slide out effortlessly
I had a great experience with CMMG, but not so much with Aero. In terms of lower parts kits, those are the two main brands I have used. I have decided not to purchase Aero’s LPK again, but I would definitely consider buying from CMMG in the future.
I was taken aback because I have used a plethora of Aero parts in the past, and they have always performed exceptionally well for me.
You can purchase LPKs from MAS Defense for only $25 with free shipping. This way, you have the freedom to customize your trigger and grip options as desired
I have had positive experiences with both the BCM and Daniel Defense kits. Both options have functioned exceptionally well for me.
LPKs manufactured by reputable brands tend to be very similar in terms of quality, so it may be wise to choose the most affordable option. Personally, I have decided to purchase the BCM enhanced LPK because it includes all the features I want in a single package – including the mod 3 grip, enhanced trigger guard, and the PNT trigger, which is comparable to the ALG ACT.
Guys, are all Lower Parts Kits the same? cause I’m a newer one I want to buy, but don’t know what I need for my AR-15
❌ No, not all Lower Parts Kits are the same. Different manufacturers may include different parts or use different materials and manufacturing processes.
⚠️ It’s important to choose a kit that is designed for your specific AR-15 model and to do your research to find a kit with a good reputation for quality and reliability. 📢 If you’re unsure of what you need, it may be helpful to consult with a knowledgeable gunsmith or experienced AR-15 owner.
My top choice for a standard LPK is CMMG, as I have found their parts to be of higher quality with better fit and finish. Another kit that I enjoyed using was the build-your-own kit from Red Barn Armory, which allowed me to avoid receiving unnecessary parts that I would later replace. The only kit that I have used and didn’t care for was from Anderson.
I find CMMG to be an excellent choice, especially because they have color-coded everything. This feature makes it incredibly easy to differentiate between various springs.
Out of all the basic LPKs I have used, the DS Arms kit from Primary Arms stands out for having the cleanest and most precise breaking trigger straight out of the box.
Why should I change a Lower Parts Kit? and how often?
1️⃣ You may want to change a Lower Parts Kit if you are building a new AR-15 rifle from scratch if you are upgrading or customizing your current AR-15, or if your current kit is worn out or damaged. The trigger and other small parts in the Lower Parts Kit can wear out over time with use, so if you notice any issues with your rifle’s performance, it may be time to replace the kit.
2️⃣ The frequency with which you should change your Lower Parts Kit depends on how often you use your AR-15 and how well you maintain it.
🔸 If you shoot frequently or put a lot of rounds through your rifle, you may need to replace the kit more often.
🔔 It’s a good idea to inspect the parts in your Lower Parts Kit periodically for wear or damage and replace them as needed. As a general rule, you should plan on replacing your Lower Parts Kit at least once every 5,000 to 10,000 rounds, or more often if you notice any issues with your rifle’s performance.
I opted for CMMG’s LPK for my build, and I have not encountered any issues with it so far. It costs approximately $35 to $40, but it doesn’t include the grip, trigger, or trigger guard.