NBS 8.5" .300 BLK Pistol M-LOK Upper Assembly
Out of stock
Built on an extruded 6061 billet upper receiver, using a steel gas block as opposed to aluminum, and the new V2 Dirty Bird M-LOK handguards. We use Permatex 242 on key components while using mil-spec AEROSHELL 33MS Anti-Seize grease on the properly torqued barrel nut and muzzle device. 300BLK is a great round for home defense and hunting. To this end, the recessed flash can directs conclusive gas and noise down range, toward the target and away from the shooter. The Dirty Bird Gen 2 Handguard features a shaved top rail, M-LOK mounting slots on every side of the handguard and feature the patent-pending ASAL locking system to ensure your handguard will not lift or slip under any circumstances. The clever anti-rotation system uses a stainless steel dowel that indexes the receiver with the handguard.
Bottom line is this: you hear all the time about guys buying a budget upper and it not lasting or having to send it back because of some hardware defect or other issue caused by a careless assembly process. That is why we use top tier components and assemble each unit to the highest standard of quality. We want your upper to function flawlessly out of the box. In fact, we guarantee it will.
Buy with confidence, this upper is backed by our 30 day satisfaction guarantee. Buy it, run it, abuse it, and if you aren’t satisfied you can send it back for a full refund.
Lifetime Warranty
Made in the USA
NBS Slick Side Billet Upper Receiver
- M4 Feedramps
- Compatible with mil-spec forged lower receivers and most billet lower receivers
- .250 takedown / pivot pin holes
- No forward assist
- Designed to be used with or without a port door / dust cover (will need to remove e-clip from dust cover pin before assembly)
- Weight: 7.1oz
Dirty Bird AR-15 SMRS Handguard – Slim M-LOK Rail System V2
Tough
- Machined from aircraft grade 6061-T6 aluminum extrusions.
- Type 3 hard anodizing or Cerakote™ sprayed at 1 mil thickness per spec.
Versatile
- M-LOK attachment slots on all sides, including the shaved portion of the top rail.
- 1913 Picatinny top rail with shaved and beveled center section.
- Snag free design with smooth, uniform octagonal surface ideal for accessory attachment or application of specialty coatings or patterns.
Practical
- This version features the patent pending anti-slip / anti-lift attachment method (ASALTM) for an easy, timing-free installation that provides an extremely rigid and secure attachment. Read below for more technical details about this impressive new attachment method.
- Compatible with most known low profile gas blocks.
Straight Forward Installation
- Using only a 1-3/16 Crow’s Foot wrench and 5/32″ Allen key
- Barrel nut does not requiring timing with the gas tube. No shims required.
The end result is a great looking, zero compromise handguard suitable for a wide variety of builds.
Interior Diameter
1.35″” ID
1.7″” Maximum Vertical ID (for considering vertical height of gas blocks)
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 | 7.1 oz |
|---|---|
| Dimensions | 20.5 × 5 × 5 in |
| Barrel Finish | Other |
| Cartridge Compatibility | 300 BLK |
| Barrel Length | 8.5" |
| Gas System Length | Pistol |
| Twist Rate | 1-7 |
| BCG / Charging Handle | Not Included |
| UPC | 999995486 |
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
- assembly
- AR Pistol
- purchases
- Dust cover
- Everything
US
Clean simple
Loved this upper only thing I didn't like was the milspec dust cover so I installed a "shaved look" dust cover and I think it looks fantastic!
USGreat upper and pricing
Great value on this upper. Everything fit great and worked flawlessly upon assembly of the AR Pistol. AR15 Discounts has been great to work with on multiple purchases as well.
