AR15 Lower Parts & Kits for Sale Up to 83% Off

Shop online for great deals on AR15 Lower Parts kits and lower receiver parts. Whether you’re looking for buffer tubes, enhanced AR 15 lower parts kits, replacement parts like takedown pins, a new trigger assembly, an ambidextrous safety selector, or lower receiver parts kits that have everything you need for a complete build kit, you’ve come to the right place! Save big today on all of the AR15 parts and gun parts you need to upgrade or complete your build.

What Are the Parts of the AR15 Lower Receiver?

Not counting the various springs, the basic parts of an AR15 lower receiver are:

Trigger Assembly
Trigger guard
Magazine catch/release
Bolt catch/release
Safety selector switch
AR 15 Pistol grip
Takedown pins
Buffer tube
Buffer & spring
Buttstock (or optional wrist brace on AR pistols)

How Many Pins Does an AR15 Lower Receiver Have?

A lower receiver typically has the following six pins:

Bolt catch roll pin
Hammer pin
Pivot pin
Takedown pin
Trigger guard roll pin
Trigger pin

Are All AR15 Lower Parts the Same?

While AR 15 lower parts are generally standardized to fit within a typical AR15 lower receiver, there are some differences and variations to consider:

Mil-Spec vs. Commercial Spec: Most AR15 Lower Parts kits (LPKs) are designed to be Mil-Spec, meaning they conform to military specifications for compatibility and interchangeability. However, there are also commercial-spec parts that might have slight differences in dimensions and quality.
Quality and Materials: Lower parts can vary in terms of the materials used and the manufacturing process. For instance, parts can be made from different grades of steel or aluminum, and some may be coated or treated to enhance durability and performance.
Enhanced Parts: Many manufacturers offer enhanced or upgraded lower parts, such as improved triggers, ambidextrous controls, and anti-walk pins. These parts can improve the performance and usability of the rifle but may have different dimensions or installation requirements.
Compatibility: While most AR15 lower parts are interchangeable among AR15 platforms, some proprietary designs by certain manufacturers may not be compatible with standard AR15 lowers. It's important to ensure compatibility, especially if you're mixing parts from different manufacturers.
Caliber Variations: Though AR15s are most commonly chambered in .223/5.56, they can also be built for other calibers like .300 Blackout, 6.5 Grendel, or 9mm. Some lower parts may be specific to certain calibers, especially those related to the magazine catch and bolt catch mechanisms.

Buy AR 15 Lower Parts Kits & Lower Receiver Parts at OpticsPlanet!

Get all of your AR 15 Lower Parts Kits and Lower Receiver Parts right here at OpticsPlanet! Check out the list below to see just a handful of the most popular top brands we carry!

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