This is a how to assemble AR15 lower guide from start to finish. Before starting, you may need these tools to help you successfully put together everything.
- Roll pin punch
- Small mallet hammer
- Receiver vice block
- Adjustable torque wrench
- Staking pin (Optional)
- Allen and hex screw driver
Step 1. Install Receiver Pins
- Place the lower receiver in a receiver vice block to secure it.
- Drive the receiver pins through the lower receiver using a roll pin punch and a small mallet hammer.
Step 2. Install Magazine Release Button
- Locate the magazine release button and spring.
- Assemble the magazine release button and spring in the lower receiver
- Ensure that the magazine release button operates smoothly.
Step 3. Install Trigger Guard
- Place the trigger guard into the lower receiver.
- Secure it using the roll pin punch and small mallet hammer.
Step 4. Install Trigger Group
- Place the trigger group into the lower receiver.
- Tighten the trigger group using an adjustable torque wrench.
- The challenging part is the hold the spring tension while trying to align the holes. A complete drop in trigger is the easiest to install.
Step 5. Install Fire Selector & Detent
- Place the fire selector and detent into the lower receiver.
- Secure it using the roll pin punch and small mallet hammer
Step 6. Install Pistol Grip
- Screw the pistol grip into the lower receiver.
- Tighten it using an Allen or hex screwdriver.
Step 7. Install Bolt Catch
- Assemble the bolt catch and spring into the lower receiver.
- Secure it using the roll pin punch and small mallet hammer.
Step 8. Install Buffer Tube
- Place the buffer tube into the lower receiver.
- Secure it using the castle nut and end plate.
- Stake the castle nut in place using a staking pin (Optional).
Step 9. Install Stock and Recoil Spring
- Place the buttstock and recoil spring into the buffer tube.
- Secure it by screwing the stock onto the buffer tube.
Be sure to know the difference between mil-spec and commercial buffer tubes