Building your own AR-15 can be a rewarding experience, offering customization and a deeper understanding of your firearm. However, navigating the world of parts can be daunting. One crucial component is the lower parts kit (LPK), which contains the essential internal components that make your lower receiver functional. This guide will help you understand what to look for when choosing the best lower parts kits for your build.
What is an AR-15 Lower Parts Kit?
An AR-15 lower parts kit is a collection of individual components that fit inside the lower receiver. These parts are essential for the firearm's operation, allowing you to manipulate the weapon, control the firing cycle, and ensure safe operation. A complete LPK typically includes:
- Hammer: Strikes the firing pin to ignite the cartridge.
- Hammer Pin: Securely holds the hammer in place.
- Trigger: Initiates the firing sequence.
- Trigger Pin: Holds the trigger and disconnector in place.
- Disconnector: Prevents automatic fire.
- Bolt Catch: Locks the bolt to the rear after the last round is fired.
- Bolt Catch Pin: Secures the bolt catch.
- Magazine Catch: Releases the magazine.
- Magazine Catch Button: The button pressed to release the magazine.
- Retaining Pin: (Sometimes included, sometimes sold separately) Used to retain other components within the lower receiver.
- Grip Screw: Used to attach the pistol grip.
Factors to Consider When Choosing a Lower Parts Kit
The quality and performance of your AR-15 are significantly influenced by the quality of your LPK. Choosing the right one involves careful consideration of several factors:
1. Material and Manufacturing Quality:
The components should be made from high-quality materials, typically 8620 steel for critical parts like the hammer and trigger. Look for parts that are precisely manufactured to ensure proper fit and function. Cheaply made parts can lead to malfunctions or even unsafe conditions.
2. Finish:
A durable finish is crucial for protecting against corrosion and wear. Hardcoat anodizing or nitriding are preferred finishes, offering superior protection compared to simpler coatings.
3. Brand Reputation:
Choosing a reputable brand is essential. Established manufacturers invest in quality control and use better materials, resulting in more reliable and durable components. Researching brands and reading reviews can help you identify trustworthy options.
4. Type of Trigger:
LPKs often come with a standard trigger, but some offer enhanced triggers, like mil-spec or upgraded triggers designed for better performance or feel. Consider your preferences and intended use of the rifle when making your decision.
5. Price vs. Value:
While budget-friendly options exist, remember that cutting corners on quality can be costly in the long run. Investing in a higher-quality LPK from a reputable manufacturer ensures reliability and longevity.
Top Considerations for Selecting Your LPK
Beyond the core features above, consider these points:
- Compatibility: Ensure the LPK is compatible with your lower receiver. Most are designed for standard AR-15 lowers, but always double-check the specifications.
- Reviews: Check online reviews from other builders. Real-world experiences can offer valuable insights into the reliability and performance of different LPKs.
- Customer Service: Choose a manufacturer with good customer service in case you encounter any problems.
Conclusion: Finding the Perfect Fit
Selecting the best lower parts kit is a crucial step in building your AR-15. By carefully considering the factors discussed above and researching different brands, you can choose a kit that meets your needs and ensures a reliable and safe firearm. Remember, a well-chosen LPK is an investment in the long-term performance and safety of your build. Thorough research and careful selection will lead to a superior AR-15 experience.
