What parts do I need to build an AR-15?

To build an AR-15, you'll need upper and lower receiver parts, a bolt carrier group, barrel, gas system, buffer system, trigger assembly, and handguard.

What’s the difference between mil-spec and custom AR-15 parts?

Mil-spec parts follow standard military dimensions and are interchangeable across builds. Custom parts offer upgraded features like enhanced ergonomics or aesthetics.

Do you carry parts for AR-15 pistols?

Yes, many of our parts are compatible with AR-15 pistol builds, including buffer systems, grips, and lower receiver components.

Can I replace individual AR-15 parts without re-building the whole rifle?

Absolutely. You can replace worn or damaged parts individually, such as springs, takedown pins, or selectors, without doing a full rebuild.

AR-15 Parts – Mil-Spec & Custom Rifle Components

Q: Are your AR-15 parts mil-spec compatible?

Yes, most of our AR-15 parts are mil-spec and designed to fit standard AR-15 platforms, including lower kits, buffer tubes, and springs.

AR-15 Mag Release

Bolt Carrier Groups

Bolt Catch

AR-15 End Plate

Gas System Parts

Recoil Parts

Safety Selector

AR-15 Springs

Takedown Pins

AR-15 Triggers

Red AR 15 Parts

AR-15 Forward Assist

Dust Cover / Ejection Port Cover

AR-15 Lower Parts Kit

AR15 Upper Parts Kit

AR-15 Barrel

**ERGO AR-15 Lower Spring Replacement Kit** $7.45

**ERGO AR-15 Upper Spring Replacement Kit** $7.45

**ERGO AR-15 Upper & Lower Spring Replacement Kit** $14.00

**Elftmann Speed Safety - Push Button AR15 Ambidextrous Safety** $37.95

**Matador Arms STINGER AR Muzzle Brake w/ Muzzle Blast Diverter** $89.99

**Geissele SSA: Super Semi-Automatic AR-15 Trigger** $240.00

**Timber Creek Outdoors AR Takedown Pin Sets** $15.99

**Timber Creek Outdoors AR Extended Magazine Release** $15.99

**Timber Creek Outdoors AR Oversized Trigger Guard** $19.19

**Timber Creek Ambidextrous Safety Selector** $31.99

**Timber Creek Outdoors QD End Plate** $15.99

**Deltac 28pc AR-15 Lower Parts Kit** $32.95

**DELTAC Ejection Port Cover kit for AR-15 (Made in USA)** $14.95

**Aim Sports Mil-Spec Flash Hider, 1/2-28** $11.95

**Timber Creek Outdoors Billet AR-15 Dust Cover** $23.95

**Aim Sports AR-15 Lower Parts Kit** $61.95

**Aim Sports AR 15 Buffer Spring** $6.95

**Timber Creek Greyman Ambidextrous AR-15 Charging Handle** $115.95

**Timber Creek Greyman Billet Dust Cover - AR15 Dust Cover** $33.95

**Timber Creek Greyman QD End Plate** $23.95

**Timber Creek Outdoors AR-15 Lower Parts Kit** $89.99

**Bcmgunfighter AR-15 Enhanced Lower Parts Kit** $119.95

AR-15 Parts – Custom & Mil-Spec Rifle Components

Whether you're upgrading a workhorse rifle or building your first custom AR-15, you need parts that perform. At Mounts Plus, we stock one of the most complete selections of AR-15 parts available online — from mil-spec essentials to enhanced components built for speed, accuracy, and reliability.

Our inventory is trusted by builders, gunsmiths, law enforcement, and serious enthusiasts because every part we carry is designed to fit right, function properly, and stand up to real-world use.

🧩 Shop Parts for your AR-15 by Category

Find exactly what you need to complete your rifle build or upgrade your existing setup:

AR-15 Lower Parts Kits – Full LPKs, fire control groups, and individual parts
Triggers & Safety Selectors – Drop-in trigger upgrades, ambidextrous safeties
Buffer Systems – Tubes, springs, buffers, and end plates (Mil-Spec + Commercial)
Upper Receiver Parts – Dust covers, charging handles, forward assists
Muzzle Devices – Brakes, flash hiders, and suppressor mounts
Spring Kits – Complete lower and upper spring sets for repair and tuning

🔧 Why Builders Trust Mounts Plus for AR-15 Parts

We understand that when you're building or maintaining an AR-15, precision and compatibility matter. That’s why every part we stock is carefully selected for quality and performance.

✅ Mil-Spec Compatible – Works with standard AR-15 lowers and uppers
✅ Tested Fitment – Reliable drop-in installation for home builds or pro setups
✅ Top Brands – ERGO, Aim Sports, Aero Precision, Timber Creek, BCM, and more
✅ USA Made – Most components are proudly made and machined in the USA
✅ Fast Shipping – In-stock items ship quickly from our Florida warehouse

💡 AR-15 Build Tip

Upgrading small components like trigger guards, takedown pins, or springs can make a big difference in ergonomics and performance. These budget-friendly parts help you personalize your AR without replacing major systems.

🛒 Featured Parts for your AR-15

Here are some of our most popular options, trusted by builders nationwide:

Timber Creek Billet Upgrades – Add style with anodized controls and guards
ERGO AR-15 Spring Kits – Complete repair or tuning sets for any rifle
Matador Arms Stinger Muzzle Brake – Recoil control with integrated blast deflector
Aim Sports Mil-Spec Kits – Affordable and reliable starter components

❓ Frequently Asked Questions

Q: Are your AR-15 parts Mil-Spec compatible?
A: Yes. Unless otherwise noted, all parts are designed to work with standard Mil-Spec AR-15 lowers and uppers.

Q: Do you offer complete lower parts kits?
A: Absolutely. We stock both full AR-15 LPKs and individual components for repairs or custom builds.

Q: Will these parts work for pistol builds?
A: Yes — our parts are compatible with AR pistols, carbines, and SPRs as long as you're using a standard lower.

Q: Where are your parts made?
A: Most of our AR-15 parts are manufactured in the USA by trusted brands that meet or exceed duty-grade specs.

🔗 Related AR-15 Components & Upgrade Guides

Looking to complete your rifle build or improve overall performance? These related pages offer the essential parts and information to help you choose the perfect stock and get the most from your AR-15:

✔️ Need a buffer tube that fits your stock? Check out our AR-15 buffer tubes — available in Mil-Spec and Commercial sizes for guaranteed compatibility.
✔️ Pair your stock with an upgraded grip from our AR-15 pistol grip collection. Ergonomic options improve control and comfort.
✔️ See more ways to enhance your setup with our curated AR-15 accessories, including slings, mounts, and charging handles.
✔️ Want tips before you upgrade? Don’t miss our helpful guides and updates on how to choose the best AR-15 stock and other performance-enhancing upgrades.

Whether you’re building a rifle from scratch or fine-tuning your current setup, Mounts Plus has the parts and knowledge to support your AR platform every step of the way.

📦 Build Better, Shoot Straighter – With AR-15 Parts from Mounts Plus
No matter your mission — competition, home defense, or tactical training — we have the components to complete your rifle the right way.