Rankin Industries Lower Parts Kit Nitride

Product Description

The Rankin Industries Lower Parts Kit Nitride is a complete lower parts kit for AR-15 pattern receivers, featuring nitride-finished components. This kit supplies the fire control group, trigger pins, safety selector, magazine catch, bolt catch, buffer retainer, and takedown hardware needed to complete a stripped lower receiver.

Built by Rankin Industries and available through Western Sport, this kit gives builders a complete set of lower receiver internals in one package. The nitride finish on key components improves surface hardness and wear resistance.

This kit suits AR-15 builders who want to assemble their own lower receiver from a stripped forging or billet unit. It pairs with any mil-spec lower receiver.

Key Facts

• Brand: Rankin Industries
• Product Name: Rankin Industries Lower Parts Kit Nitride
• SKU: RI-assemblers-special-nitride
• Finish: Nitride

What a Lower Parts Kit Does

A lower parts kit contains all the small components needed to turn a stripped AR-15 lower receiver into a functional firearm chassis. The fire control group controls trigger function and hammer release. The magazine catch holds and releases the magazine. The bolt catch locks the bolt carrier group open after the last round fires. The safety selector blocks the trigger until rotated to the fire position.

Without these parts, a stripped lower receiver is just a machined piece of aluminum. A complete lower parts kit is the bridge between a raw receiver and a shootable rifle.

Nitride Finish on AR-15 Parts

Nitride is a surface treatment that diffuses nitrogen into steel, creating a thin hardened layer that resists wear and corrosion. On fire control components, nitride reduces friction between moving parts and extends service life under repeated cycling.

Nitride differs from coating finishes like phosphate or Cerakote because it penetrates the steel rather than sitting on top. This makes it more durable under high-friction conditions like trigger and hammer pin contact points.

Building an AR Lower in Texas

In Texas, building your own AR-15 from a stripped lower receiver is legal for personal use, provided you are not prohibited from owning firearms. The lower receiver itself is the serialized firearm and must be transferred through an FFL if purchased online or out of state.

Once you take possession of the lower, you can install lower parts yourself with basic hand tools. Most builders complete a lower receiver assembly in under an hour.

Ordering from Western Sport

Order online and it ships straight to your door. Western Sport has been a licensed FFL/SOT dealer since 2007, and everything we sell carries the full manufacturer warranty. Questions before you order? Send us a message.

Frequently Asked Questions

Q: Does the Rankin Industries Lower Parts Kit Nitride fit all AR-15 lowers?

A: This kit is designed for mil-spec AR-15 lower receivers. It fits most forged and billet lowers that follow mil-spec dimensions. If you have a proprietary or non-standard lower receiver, send us a message to confirm fitment before ordering.

Q: What tools do I need to install a lower parts kit?

A: Installing a lower parts kit typically requires a hammer, punch set, needle-nose pliers, and a lower receiver vise block or clamp. Some builders also use a trigger guard roll pin punch and a bolt catch roll pin starter. The process does not require specialized gunsmithing tools for most mil-spec receivers.

Q: How does a nitride lower parts kit compare to a standard phosphate kit?

A: Nitride provides a harder, more wear-resistant surface than phosphate coating. Nitride-treated fire control components typically show less friction wear at pin contact points over thousands of trigger pulls. Phosphate is a traditional military finish that offers good corrosion resistance but does not harden the underlying steel the way nitride does.

Q: Do I need an FFL transfer to buy a lower parts kit in Texas?

A: No. A lower parts kit does not contain a serialized receiver or any component regulated as a firearm. It ships directly without requiring an FFL transfer. Only the stripped or complete lower receiver itself requires transfer through a licensed dealer.

Additional information