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 |
| Weight | 57.6 oz |
|---|---|
| Dimensions | 32 × 5 × 5 in |
| Barrel Finish | Nitride / Melonite |
| Barrel Profile | Government / SOCOM |
| Gas System Length | Rifle |
| Barrel Length (inches) | 20 |
| Barrel Chamber | 5.56 NATO |
| Twist Rate | 1-7 |
| BCG / Charging Handle | Not Included |
| UPC | 4465 |
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
- Reviews
- Questions
US
Nice 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
USGood to go.
I added a charging handle and a carrier with bolt. Checked the head space a little tweaking and good to go. Shot well at a 100yrds.,will try farther after break in process.
USNBS 20 inch
I bought this upper and it spent several months waiting on me to finish my lower to put it on. I finely got the build done and the rifle would not function. It would fire but not eject the spent case. Took it home disassembled it, cleaned lubed and went back to the range. Same issue, I sent an email to AR15 with full details of my issues. They responded quickly with a shipping label and had me return it with my BCG and CH that I used for the build. They determined my gas tube was slightly undersized and they corrected it. Once work was completed they sent me a quick video showing my upper firing correctly and shipped it back to me. Just got back from the range today and the rifle is running like a champ. Great product for the cost, but more importantly excellent customer service by the AR15 team. Feel safe buying an NBS branded item, they stand by it.
