Do AR-15 uppers come with bolt carrier groups and charging handles?

Some complete uppers include a bolt carrier group (BCG) and charging handle, while others do not. Check the product listing for included parts.

Can I use a .300 Blackout upper on a 5.56 lower?

Yes, .300 Blackout uppers can be used on a 5.56 AR-15 lower, but you must use .300 Blackout ammo and compatible magazines to ensure proper function and safety.

Are these uppers legal for use on AR pistols or SBRs?

Yes, but if you're using a barrel shorter than 16 inches, you must pair it with a registered pistol lower or have proper ATF paperwork for an SBR configuration.

Which AR-15 upper is best for home defense?

A short-barrel upper in .300 Blackout with M-LOK rail and suppressor-ready threading is ideal for home defense due to reduced muzzle flash and better performance in confined spaces.

AR-15 Uppers – Complete Upper Receivers & Assemblies

Name: AR-15 Uppers
Brand: Mounts Plus
Availability: InStock

**BCM M4 Upper Receiver Assembly (w/ Laser T-markings)** $151.84

**Sharps Bros Billet Upper Receiver – AR15 | SBUR04** $194.70

**SilencerCo Sco15 Upper Receiver Blk** $219.00

**Aero Cmplt Upper 5.56 10.5" Moe Fde** $428.60

**Aero M4e1-t Upper 300blk 8" Fde** $585.10

**BATTLEARMS 10.5 Upper Wrkhorse 5.56 Ambidextrous Blk** $694.45

**Gemtech Gvac 16" 5.56 Nato Upper Blk** $751.21

**"Maxim Pdx Upper 5.56 5.5" Blk"** $1,165.50

**"Maxim Pdx Upper 300blk 5.5" Arid"** $1,165.50

**"Maxim Pdx Upper 300blk 5.5" Blk"** $1,165.50

**Noveske Chainsaw 5.56 10.5" Mlok Upper** $1,155.78

**Noveske Chainsaw 300blk 8" Mlok Upper** $1,106.76

**BATTLEARMS 10.5 Upper Auth Elite 5.56 C Gray** $999.16

**BATTLEARMS 10.5 Upper Auth Elite 5.56 C Blk** $833.84

**BATTLEARMS 10.5 Upper Auth Elite 556ambi Blk** $833.84

**BATTLEARMS 10.5 Upper Wrkhorse 5.56 Ambidextrous Gray** $832.85

**Radian Upper 10.5 .223 Wylde Brown** $1,904.95

**Radian Upper 10.5 .223 Wylde Odg** $1,904.95

**Radian Upper 10.5 .223 Wylde Gray** $1,904.95

**Radian Upper 10.5 .223 Wylde Black** $1,904.95

**Radian Upper 9 300 Blk Odg** $1,829.95

**Radian Upper 10.5 .223 Wylde Fde** $1,904.95

**Radian Upper 9 300 Blk Fde** $1,829.95

AR-15 Uppers – Complete Upper Assemblies for Custom Builds

Explore the best AR-15 uppers for your next rifle build or upgrade. Whether you're constructing a new carbine from the ground up or upgrading your existing setup, our selection of complete AR-15 upper receivers offers the reliability, precision, and modularity serious shooters demand.

From .223/5.56 NATO to .300 Blackout, and from 10.5-inch SBR uppers to 16-inch M-LOK rail systems, we’ve got premium brands like BCM, Aero Precision, Noveske, and Radian in stock and ready to ship.

🔧 Top AR-15 Uppers by Category

Model / Brand	Caliber	Barrel Length	Rail System	Price
BCM M4 Upper Receiver Assembly	5.56 NATO	16"	T-marked, flat top	$151.60
Aero Precision M4E1 300BLK Upper	.300 Blackout	8"	FDE, M-LOK	$585.78
Noveske Chainsaw Upper 300BLK	.300 Blackout	8"	M-LOK	$1,106.95
Radian Model 1 Upper .300 Blackout	.300 Blackout	9"	Flat top M-LOK	$1,829.95

✅ Mil-Spec & match-grade options
✅ Compatible with most AR-15 lower receivers
✅ Choose from forged or billet upper designs
✅ Great for custom builds, hunting, home defense, and competition

⚙️ Why Buy a Complete AR-15 Upper?

✔️ Easy Installation – Mates to any standard AR-15 lower with two pins
✔️ No Gunsmithing Required – Comes pre-assembled with barrel, rail, and BCG (select models)
✔️ Modular Upgrades – Easily swap calibers or setups without rebuilding your rifle
✔️ Tested Reliability – Built by proven manufacturers and vetted by pros
✔️ NFA Ready – Pair short-barrel uppers with pistol lowers or SBR configurations

Skip the hassle of sourcing individual parts. A complete upper lets you get on the range faster—with better performance from day one.

📏 Caliber Options

5.56 NATO / .223 Remington – Most common for general-purpose AR builds
.300 AAC Blackout – Ideal for suppressed use and short-barrel configurations
9mm Uppers – Pistol-caliber carbines with Glock mag compatibility (by request)
.22LR Uppers – Great for training or small game use (available upon request)

🧠 Key Features to Consider

Barrel Lengths: From 7.5” to 16” — SBR, CQB, or full-length options
Handguard Type: M-LOK, KeyMod, or quad rail
Gas System: Carbine, mid-length, or pistol
BCG & Charging Handle: Some uppers include them; others allow customization
Finish: Hardcoat anodized, Cerakote, or custom coatings

❓ Frequently Asked Questions

Q: Will these AR-15 uppers work with my lower receiver?
A: Yes. All AR-15 uppers listed are Mil-Spec compatible and will fit standard AR-15 lower receivers unless otherwise stated.

Q: Do these come with BCG and charging handle?
A: Some models are complete, including the bolt carrier group and charging handle. Others are upper-only, allowing customization. Check product details.

Q: Can I install a .300 Blackout upper on my 5.56 lower?
A: Yes. The lower is compatible—but ensure you're using .300 Blackout mags and ammo to match the upper.

Q: Are these legal to use on a pistol lower?
A: Yes—if you're using an upper under 16" with a registered pistol lower or an approved SBR (NFA-compliant setup).

Q: What’s the best upper for home defense?
A: A short-barrel .300 Blackout upper with a suppressor-ready rail is ideal for low-light, indoor use. We recommend models from Aero and Radian.

🔗 Related AR-15 Accessories

🛒 Why Mounts Plus?

✔️ Trusted by AR builders since 1994
✔️ Top brands in stock and ready to ship
✔️ Expert support & compatibility advice
✔️ Veteran-owned, shooter-run operation
✔️ Fast U.S. shipping with secure checkout

🔥 Build Smarter. Shoot Better.

Ready to build the AR-15 you’ve always wanted? Our selection of AR-15 uppers gives you the tools to take your performance to the next level—whether you’re shooting 5.56, .300 BLK, or beyond.

➡️ Shop AR-15 Uppers Now at Mounts Plus
➡️ Pre-Assembled. Precision-Built. Range-Ready.