Lower Assembly Parts List

Recommended Tools

Getting Started

Install Magazine Release

• Using your magazine release spring, button, and magazine release bar. If you’re using a right-handed lower receiver, place the magazine release bar from the right side, then slide the spring over the bar from the left side

• Start the magazine release button on the threads of the magazine release bar. Once it is started and you’re not able to turn it anymore you can press the magazine button on the receiver, and continue turning the magazine release bar from the other side.

Install Bolt Release

Install Trigger Guard (if applicable)

Install Trigger Assembly

Install Trigger and Trigger Spring

• Take your trigger spring and slide it over the arms on either side of the trigger. The two legs of the trigger spring will be pointed downwards so they’ll sit flat in the receiver, the and top loop portion of the trigger spring sits under the front belly of the trigger as shown in the photo
  

Insert Disconnector Spring

• The channel on the top of the trigger has a small hole for your disconnector spring to sit. The disconnector spring is cone-shaped. Place the wider end of the spring into the spot on your trigger, and the more narrow end pointing upwards.

Install Disconnector and Bottom Trigger Pin

• Your Disconnector will sit inside the channel on top of your trigger, a small cut-out on your disconnector will line up for the top part of the disconnector spring to sit.
  
• Insert the trigger and disconnector assembly into the lower receiver, and press down on the unit until the forward bottom hole in the lower receiver lines up with the trigger and the disconnector holes
  
• Insert the Trigger pin into the side making sure everything lines up. There may be some difficulty with getting everything to line up. Don’t use too much force to insert the pin, but a small mallet can be used to help guide the trigger pin in so it sits flush on both sides of the lower receiver
  
• After getting the trigger and disconnector into place, the trigger should pivot freely.
  

Install Hammer Spring (Proper Orientation)

• To install the hammer, place the legs of the spring downwards behind the trigger pivot. Load the spring while pressing downwards until the hole on the hammer assembly lines up with the hammer pin hole

Install Safety Selector

• Slide the safety selector switch into place so it sits flat against the side of the receiver.
  

Install Grip and Safety Selector Detent

Install Buffer Assembly

Install Rear Takedown Pin, Spring, and Detent

• Your rear takedown pin spring and detent are held in place using the end plate of your rifle. Before you turn your buffer tube into place, you’ll need to insert the detent, spring, and takedown pin. Then use a small punch to depress the spring into the receiver enough to be able to twist the buffer tube and end plate into place over the top of the spring. Be very careful not to pinch, fold, or bend that spring as you attempt to cover it with the end plate

Thread in Buffer Tube, End Plate, and Castle Nut

• Twist your castle nut onto your buffer tube, and twist it on all the way back so you have room to slide your end plate on.

• Twist your buffer tube onto the threads of your rear receiver until the notch on your buffer tube engages with your buffer retainer pin. Depress the retainer pin and spring while twisting the buffer tube into place. The buffer retainer pin will snap into place inside the end of the notch on your buffer tube.

And you're all set! You should now have a fully assembled lower receiver ready to pair with your Complete Upper Build.

Any additional tips you would like to share with your fellow gun builders? Leave a comment below!

Did one of your springs or detents launch off into oblivion never to be found again? Don't worry, it happens! We've put together a "Lost Parts" kit just for you. That can be found HERE.