Understanding the various lower parts of an AR-15 is essential for those interested in building, customizing, or maintaining this firearm. The lower receiver is a critical component, and it houses several smaller parts that play specific roles in the rifle’s operation. Here’s an overview of the different AR-15 lower parts:

1. Lower Receiver:

• The lower receiver is the serialized component of the AR15 Parts, and it’s considered the firearm under U.S. law. It houses the fire control group and other essential parts.

2. Fire Control Group (FCG):

• The fire control group consists of several parts that enable the shooter to control the firearm’s firing process:
  • Trigger: When pulled, releases the hammer.
  • Hammer: Strikes the firing pin, initiating the firing sequence.
  • Disconnect: Prevents the firearm from firing automatically in semi-automatic mode.
  • Trigger Spring and Hammer Spring: Provide tension to the trigger and hammer.

3. Trigger Guard:

• The trigger guard surrounds the trigger and protects it from accidental discharges. Some AR-15s have a removable trigger guard for improved access, especially when wearing gloves.

4. Pistol Grip:

• The pistol grip is where the shooter holds the firearm. It can be replaced with various aftermarket grips to enhance comfort and ergonomics.

5. Magazine Catch:

• The magazine catch, also known as the mag catch or mag release, is a button or lever that releases the magazine from the lower receiver when pressed. It allows for the quick removal of an empty magazine.

6. Magazine Release Button:

• The magazine release button is a component that operates in conjunction with the magazine catch. Pressing it allows the magazine to drop free when the mag catch is engaged.

7. Bolt Catch (Bolt Hold-Open):

• The bolt catch is a lever that, when engaged, locks the bolt carrier group (BCG) to the rear after the last round is fired, indicating that the magazine is empty. It can also be manually activated to lock the BCG open.

8. Safety Selector (Safety Switch):

• The safety selector is a lever that allows the shooter to choose between “safe” and “fire” positions. It blocks the trigger when in the “safe” position, preventing the firearm from discharging.

9. Takedown Pins (Front and Rear):

• Takedown pins are push-button or captured pins that hold the upper and lower receivers together. They allow for field-stripping the firearm for cleaning and maintenance.

10. Buffer Tube (Receiver Extension): – The buffer tube, or receiver extension, is an essential part of the AR-15’s recoil system. It houses the buffer and buffer spring, which control recoil and cycling.

11. Buffer and Buffer Spring: – The buffer is a weight that, along with the buffer spring, helps control recoil and return the BCG to the forward position after firing.

12. Stock or Brace: – The stock or brace attaches to the buffer tube and is used for shouldering and stabilizing the firearm.

Understanding these AR-15 lower parts is vital for assembling, maintaining, and customizing your rifle. It’s essential to follow safety guidelines and regulations when working with firearms and their components, especially when building or modifying AR-15s. Additionally, consulting the manufacturer’s instructions and seeking guidance from experienced firearm enthusiasts can be valuable when working on your AR-15 lower receiver.