Anderson Lower Parts Kit w/ Stainless Hammer & Trigger – G2-K421-A000-0P
Pros & cons
What works
- Weighs 6.2 oz — lighter than many assembled lowers with similar components
- Includes 24 parts — eliminates sourcing time and compatibility guesswork
- Stainless steel hammer and trigger — resist corrosion better than carbon steel
Trade-offs
- 5.5 lb trigger pull — heavier than competition-grade triggers like Timney at 3.5 lb
- No anti-rotation pins — may require additional purchase for high-round-count builds
- A2 pistol grip — basic design lacks ergonomic contours of modern grips
Video review
Expert review
Specs at a glance
About this product
What is the Anderson Lower Parts Kit w/ Stainless Hammer & Trigger – G2-K421-A000-0P?
The Anderson Lower Parts Kit w/ Stainless Hammer & Trigger – G2-K421-A000-0P is a complete drop-in kit for AR-15 lower receivers that includes all necessary components for assembly, featuring a stainless steel hammer and trigger for enhanced durability and smoother operation. This kit is engineered for builders who want reliable performance without sourcing individual parts. Every component is pre-fitted to reduce installation time and ensure compatibility with mil-spec lowers.
What is the Anderson Lower Parts Kit used for?
The Anderson Lower Parts Kit is used for assembling or upgrading an AR-15 lower receiver with all necessary internal components in one package. It includes everything from the bolt catch to trigger pins, saving time and reducing the risk of missing parts during a build. The stainless steel hammer and trigger resist corrosion and provide a consistent pull weight of approximately 5.5 pounds.
How does the Anderson Lower Parts Kit compare to the Glock-Mod Glock 3.5lb Modified Cut Nub Connector?
The Anderson Lower Parts Kit is better for full AR-15 lower builds, while the Glock-Mod Glock 3.5lb Modified Cut Nub Connector is optimized for Glock pistols with a lighter trigger pull. The Anderson kit offers comprehensive coverage with 24 components, versus the Glock-Mod's single connector part. If you're building an AR-15 from scratch, this kit is more efficient; for Glock upgrades, consider the Glock-Mod connector.
What does it weigh and what are the dimensions?
The entire kit weighs 6.2 ounces and comes packaged in a compact box measuring 4.5 x 3.2 x 1.1 inches. Individual components like the stainless steel hammer weigh 0.8 ounces, and the trigger is 0.6 ounces, contributing to a lightweight yet robust build. The small package size makes it easy to store or transport without bulk.
Who is this NOT for?
This kit is not for users seeking high-performance competition triggers or custom finishes, as it uses standard mil-spec components without enhanced features. If you need a lighter pull weight or specialized materials like aluminum triggers, look at options like the Glock-Mod BLEM Standard Semi-Auto Trigger. It's also unsuitable for non-AR-15 platforms.
What's in the box?
The box contains 24 components: bolt catch, bolt catch plunger, bolt catch roll pin, bolt catch spring, buffer retainer, buffer retainer spring, disconnect, disconnect spring, stainless hammer, hammer pin, hammer spring, magazine catch, magazine catch button, magazine catch spring, A2-style pistol grip, pistol grip lock washer, pistol grip screw, pivot pin, pivot pin detent, pivot pin detent spring, selector, selector detent, selector detent spring, takedown pin, takedown pin detent, takedown pin detent spring, stainless trigger, trigger guard, trigger guard roll pin, trigger pin, and trigger spring. Everything is organized to prevent loss during installation.
Is the Anderson Lower Parts Kit worth it at $44.95?
At $44.95, this kit is worth it for builders prioritizing reliability and completeness over premium features. It saves approximately 20 minutes compared to sourcing parts individually and eliminates compatibility concerns. For the price, you get corrosion-resistant stainless components that outperform basic kits with carbon steel parts.
Key attributes
| Weight | 6.2 oz |
| Trigger Pull | 5.5 lb |
| Material | Stainless steel hammer and trigger |
| Components | 24 pieces |
| Compatibility | Mil-spec AR-15 lowers |
| Pistol Grip | A2 style |
Frequently asked questions
- Is it compatible with mil-spec AR-15 lowers?
- Yes, it's fully compatible with mil-spec AR-15 lowers, including brands like Anderson, PSA, and Aero Precision. The components adhere to standard dimensions, ensuring no fitment issues. Installation typically takes under 30 minutes with basic tools.
- Does it fit polymer lowers?
- It fits most polymer lowers designed for mil-spec parts, but check manufacturer specifications for compatibility. Some polymer lowers may require slight modifications due to tolerance variations. Avoid using with non-mil-spec designs to prevent wear.
- How long does shipping take?
- Standard shipping takes 3-5 business days within the continental US, processed through USPS or FedEx. Expedited options are available for an additional fee, reducing delivery to 1-2 days.
- Can I return it if it doesn't fit?
- Returns are accepted within 30 days if the product is unused and in original packaging, subject to a 15% restocking fee. Contact support with order details to initiate the process, which takes 5-7 business days for refund processing.
- Does this work with aftermarket triggers?
- The included stainless trigger is designed for use with the kit, but it can be replaced with aftermarket triggers if desired. Ensure any alternative trigger is mil-spec compatible to avoid function issues. The hammer and other parts will work with most drop-in triggers.