My Cart: 0 item(s)
AR-15 Parts – Custom & Mil-Spec Rifle Components | MSP
AR-15 Parts – Custom & Mil-Spec Components for Every Rifle Build
Everything You Need to Build, Repair, or Upgrade Your AR
Whether you're assembling your first rifle or upgrading a trusted platform, you’ll find the AR-15 parts you need right here at Mounts Plus. We stock a complete range of mil-spec and enhanced AR-15 components, all selected for reliability, compatibility, and performance.
From small springs and detents to full lower parts kits and buffer assemblies, our inventory is built for builders who demand quality. Every part we carry is tested for fitment and built to handle the real-world demands of tactical, competition, or defensive use.
🔧 Shop AR-15 Parts by Category
-
Lower Receiver Parts – Triggers, takedown pins, safeties, springs, grips, and full LPKs
-
Upper Receiver Parts – Forward assists, dust covers, charging handles, and ejection port covers
-
Bolt & Gas System Parts – Bolt catch, gas keys, cam pins, cotter pins, and gas rings
-
Recoil System Parts – Buffers, buffer tubes, end plates, and springs
-
Muzzle Devices & Mounts – Muzzle brakes, compensators, and thread protectors
-
Ambidextrous & Enhanced Controls – Safety selectors, mag releases, and trigger guards
🔍 What Makes Our AR-15 Parts Different?
-
✅ Mil-Spec Compatible – Seamless fit with standard AR-15 lower and upper receivers
-
✅ Trusted Brands – ERGO, Aero Precision, CMC, Timber Creek, Aim Sports, and more
-
✅ Precision Machined – Clean tolerances for easy installation and smooth function
-
✅ Made in the USA – Most parts are U.S.-manufactured to exceed duty-grade standards
-
✅ Fast Shipping – Parts in stock, ready to ship directly from our Florida facility
💡 Featured AR-15 Parts
ERGO AR-15 Spring Kits
-
Complete spring sets for upper and lower receiver maintenance
-
Great for backups, repairs, and fine-tuning
Timber Creek Billet Upgrades
-
Oversized trigger guards, takedown pins, and QD end plates in anodized finishes
-
Perfect for adding style and enhanced ergonomics
Matador Arms Stinger Muzzle Brake
-
Muzzle brake and blast deflector in one
-
Ideal for home defense and indoor training setups
Aim Sports Mil-Spec Kits
-
Affordable parts kits and accessories for AR-15 builds
-
Great for budget-minded builders and spares
✅ Compatibility
-
Works with all mil-spec AR-15 receivers
-
Fits .223/5.56 NATO, .300 Blackout, 6.5 Grendel & more
-
Drop-in ready parts with standard pin sizes and threading
-
Compatible with most DIY AR builders, gunsmiths, and OEM repair setups
🛠️ Building vs. Replacing?
Whether you're:
-
🧱 Building from scratch (using a stripped lower)
-
🧰 Repairing worn components
-
⚙️ Upgrading performance parts
…we have the right AR-15 parts to support your build from the ground up.
Frequently Asked Questions
What are the essential AR-15 parts needed for a build?
At minimum, you'll need a complete lower parts kit, upper parts, buffer system, and fire control group. Optional parts include muzzle devices and accessories.
Are your AR-15 parts mil-spec?
Yes — unless otherwise noted, all parts are designed for compatibility with mil-spec AR-15 lowers and uppers.
Can I buy parts individually?
Absolutely. We offer both complete kits and individual AR-15 parts for custom builds, maintenance, or replacement.
Are these parts compatible with pistol or rifle builds?
Yes. As long as you're using a standard AR-15 lower, these parts work for pistol, carbine, or SPR configurations.
Where are these parts made?
Most of our AR-15 parts are made in the USA by trusted defense and commercial manufacturers.
🔗 Related Product Categories
🔩 Ready to Build? We’ve Got You Covered
From critical small parts to complete upgrade kits, Mounts Plus has the AR-15 parts you need to keep your rifle running at its best. Whether you’re fine-tuning performance or replacing worn components, we’ve got your six.
Shop now and build it better with Mounts Plus — the AR parts pros.