Moriarti AR-15 .338 ARC 16" Upper Assembly – 12" M-LOK, A2 Flash Hider
| Brand: | Moriarti Armaments |
| Product Code: | MAR-338-16-A2 |
| Availability: | In Stock |
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$299.95
- $449.95
.338 ARC Upper: Specs & Features
Step up your AR game with the Moriarti AR-15 .338 ARC 16" Upper Assembly, built for enhanced energy delivery, accuracy, and control. This upper is engineered to maximize the ballistic potential of the .338 Advanced Rifle Cartridge (ARC), delivering optimal performance for both hunting and long-range shooting.
With a durable 16” medium-profile barrel, a pistol-length gas system for smooth cycling, and a 12” M-LOK free-float rail for complete accessory modularity, this build is a precision powerhouse.
Key Features:
Barrel
- Length: 16"
- Chamber: .338 ARC
- Profile: Medium
- Twist Rate: 1:8 – ideal for stabilizing a wide range of bullet weights
- Thread: 5/8x24
- Muzzle Device: A2 Flash Hider – reduces flash signature and improves muzzle control
- Material: 4150 Chrome Moly Vanadium (4150V)
- Finish: Black Nitride
- Weight: 30 oz
Gas System
- Type: Pistol-Length
- Gas Block: .750” low profile steel
Upper Receiver
- A3 Flat Top forged from 7075-T6 aluminum
- Hardcoat anodized, mil-spec
- Includes forward assist and dust cover
Handguard
- 12” Moriarti Slim M-LOK Free Float Rail
- Aircraft-grade aluminum construction
- Full M-LOK compatibility at 3, 6, 9 o'clock positions
- Ergonomic and ventilated for better grip and cooling
Estimated Velocity by Barrel Length (200–225 gr supersonic loads)
| Barrel Length | Velocity (200–225gr) | Use Case |
|---|---|---|
| 10.5" | ~1,500–1,600 fps | Compact / suppressed builds |
| 12.5" | ~1,700–1,800 fps | Short-range and suppressed use |
| 14.5" | ~1,900–2,000 fps | General Use / Carbine Builds |
| 16" | ~2,000–2,100 fps | Best Energy for Hunting |
| 18" | ~2,150–2,250 fps | Max Range, Heavy Bullet Loads |
Suggested Pairings
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Looking for a custom finish? Explore Moriarti Builder Sets
Proudly made in the USA by Moriarti Armaments
Does not come with BCG and Charging Handle. Images may not be an exact representation of the product.
FAQ
Will this upper fit my AR-15 lower?
Yes. It fits a standard mil-spec AR-15 lower receiver.
What bolt do I need?
A 6.5 Grendel / .338 ARC bolt, which shares the same bolt face. A standard 5.56 bolt will not work.
Related: .338 ARC uppers · all AR-15 upper assemblies
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Tags: 338 arc upper, ar-15 338 arc upper, 16 inch upper, a2 flash hider