We set out to make one of the most affordable complete uppers, without sacrificing the integrity of the complete upper, and most important the rifle. The NBS 20″ 5.56 Rifle M-LOK Upper Assembly, is a great all around upper, especially for hunting or long-range target practice. With higher velocity and a longer sight radius with this 20″ barrel, we wanted to make sure that any shooter could take this out and shoot long distances, reliably. This upper features a 20″ NBS Government Contour barrel chambered in 5.56 with a 1:7 twist and a rifle gas system. The government profile is a great way to round out your build and not have an upper too light or too heavy. With the NBS line we wanted to make sure that we used quality products that wouldn’t break the bank. This means using a nitrided steel gas block from APOC Armory as opposed to aluminum and using quality internals like one of our classic NBS 20″ rifle barrels.
Made in the USA
Lifetime Warranty
| Upper Receiver | NBS – 7075 Aluminum – Pairs beautifully with any mil-spec lower – M4 Feedramps |
| Barrel | NBS 20″ Black Nitride 4150 Steel Government Barrel, 5.56 NATO, Rifle Length Gas System w/ 1:7 Twist |
| Gas System | Rifle Length – APOC Armory Nitrided Steel Gas Block – Stainless Steel Rifle Length Gas Tube |
| Handguard | 15″ NBS M-LOK Free Float Handguard – American Made – 6061 Aluminum*Handguard style may vary |
| Muzzle Device | Mil-Spec A2 Birdcage w/ Jet Black Nitride Finish |
NBS — Our In-House Brand for Builders Who Demand Reliable Performance and Real Value.
Designed for builders who demand reliable performance and real value without unnecessary hype or inflated pricing. NBS stands for "No Bullshit."
Built on Strong Industry Partnerships
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.
Quality You Can Trust
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.
Complete Solutions for Serious Builders
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.
Backed by a Limited Lifetime Warranty
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 | 57.6 oz |
|---|---|
| Dimensions | 32 × 5 × 5 in |
| Barrel Finish | Nitride / Melonite |
| Barrel Profile | Government / SOCOM |
| Cartridge Compatibility | 5.56 NATO |
| Barrel Length | 20 |
| Gas System Length | Rifle |
| Twist Rate | 1-7 |
| BCG / Charging Handle | Not Included |
| UPC | 999994465 |
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.
Customer Reviews
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US
20” upper
Good quality upper
USRifle Upper
Looks great and mated up with an Aero lower with no issues. Can’t wait till next range day.
USNice upper
The whole kit has quality components
USNBS 20" 5.56 upper
My order arrived in a timely fashion. I attached it to an Aero Precision lower which I also purchased from AR-15 Discounts. I've been building AR-15s from the ground up for over 45 years. And there's no better place to buy from than the folks at AR-15 Discounts! Whether it's the bare bones parts to build or complete weapons!
US20” upper
I love it I recommend
