NBS 4.5" 5.56 Nato Micro Pistol Medium 1:5 4150 Black Nitride AR-15 Barrel - 556MP4.5MED50B5
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Discover the ultimate in compact firepower with the 4.5″ 5.56 NATO Micro Pistol Medium 1:5 4150 Black Nitride AR-15 Barrel. Engineered for tactical enthusiasts and home defense setups, this ultra-short barrel delivers exceptional maneuverability without compromising on reliability or performance. Ideal for building a lightweight AR-15 pistol, it combines a rapid 1:5 twist rate for superior bullet stabilization with a durable black nitride finish that resists corrosion and extends barrel life.
Key Features
- Ultra-Compact Design: At just 4.5 inches, this micro pistol barrel enhances close-quarters handling, making it perfect for dynamic environments where every inch counts.
- Fast 1:5 Twist Rate: Optimized for heavier 5.56 NATO projectiles, ensuring tight groups and consistent accuracy even in high-stress scenarios.
- Black Nitride Finish: Provides superior wear resistance, reduced friction, and easier cleaning, keeping your AR-15 running smoothly round after round.
- Medium Profile Construction: Balances weight and rigidity, offering a lightweight 12 oz option that maintains structural integrity under rapid fire.
- Micro Gas System: Tailored for pistol-length configurations, promoting reliable cycling with minimal recoil for enhanced control.
Technical Specifications
- Caliber: 5.56 NATO
- Barrel Length: 4.5 inches
- Material: 4150 Chrome Moly Vanadium Steel
- Twist Rate: 1:5 RH
- Gas System: Pistol (Micro)
- Gas Block Journal: 0.750 inches
- Muzzle Threads: 1/2×28
- Finish: Black Nitride (Melonite)
- Platform: AR-15
- Weight: 12 oz
Why Choose This AR-15 Pistol Barrel?
Short-barreled AR-15 pistols demand components that can handle intense use while prioritizing portability. This barrel addresses common challenges like excessive muzzle flash and reduced velocity by featuring a robust 4150 steel core and nitride treatment for heat dissipation and longevity. Users appreciate its compatibility with standard AR-15 uppers, allowing seamless integration into custom builds. Whether for personal protection or range experimentation, it empowers shooters to achieve pinpoint accuracy in confined spaces, solving the pain points of bulkier setups with its sleek, efficient profile. Backed by precision manufacturing, this barrel ensures your firearm performs when it matters most.
Elevate your AR-15 build today with this high-performance 4.5″ 5.56 NATO barrel. Its blend of compact design, advanced rifling, and protective finish makes it a must-have for discerning shooters seeking reliability and versatility. Secure yours now and experience the difference in your next build.
Frequently Asked Questions
What type of ammunition works best with this barrel? This 1:5 twist excels with heavier 62-grain or 77-grain 5.56 NATO rounds for optimal stabilization, though it handles standard loads effectively.
Is the micro gas system reliable for suppressed use? Yes, the pistol-length micro gas system is designed for efficient cycling, especially when paired with suppressors, reducing gas blowback while maintaining function.
Does this barrel fit standard AR-15 receivers? Absolutely, it’s fully compatible with mil-spec AR-15 platforms, ensuring easy drop-in installation for pistol configurations.
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Through the strong partnerships AR15Discounts has built with trusted suppliers and vendors, we regularly gain access to premium components often manufactured by or for leading industry names. By purchasing these in volume, we bring them to you under the NBS label, ensuring proven quality reaches your build at a fair price, without the added cost of extensive marketing.
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Every NBS product is specified to the exacting standards we apply to our own rifles. Each component features precision CNC machining, American-made key components where it counts, robust materials, dependable steels, and durable finishes engineered for long-term reliability. These items are either sourced from reputable OEMs or carefully assembled in-house using established name-brand elements, maintaining consistent excellence throughout the lineup.
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From stripped and complete uppers to bolt carrier groups, handguards, lower parts kits, and beyond, NBS provides a unified, affordable selection that allows you to complete confident, high-performing builds.
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All NBS products come with our Limited Lifetime Warranty for the original owner, covering defects in materials and workmanship. AR15Discounts stands firmly behind these parts because, as shooters ourselves, we use and trust them, delivering honest value and gear you can rely on.
| Weight | 12 oz |
|---|---|
| Dimensions | 3.5 × 3 × 3 in |
| Finish | Nitride / Melonite |
| Barrel Profile | Medium |
| Cartridge Compatibility | 5.56 NATO |
| Gas Block Journal | 0.75 |
| Barrel Length | 4.5" |
| Gas System Length | Pistol |
| Platform | AR-15 |
| Twist Rate | 1:5 |
| Muzzle Thread Pattern | 1/2×28 |
| MPN | 556MP4.5MED50B5 |
| UPC | 29052 |
Compliance
NFA (National Firearms Act) compliance is crucial for legal ownership and transfer of regulated firearms and accessories like short-barreled rifles, suppressors, and certain types of ammunition, ensuring adherence to federal regulations to avoid legal penalties and ensure responsible firearm ownership.
