Custom Build 6mm ARC Complete Upper

$1,326.01


Firearms with barrels less than 16" overall may be subject to NFA requirements. You are responsible for ensuring your build is compliant with state and federal laws. The Plan B (LONG) specs are: Overall length: 2.82" Added length to barrel: ~2.32" (will qualify a barrel 13.9" or longer) From tip to taper: 1.5"
Firearms with barrels less than 16" overall may be subject to NFA requirements. You are responsible for ensuring your build is compliant with state and federal laws. The Plan B (SHORT) specs are: Overall length: 1.750" Added length to barrel: ~1.25" From tip to taper: 0.950"
Firearms with barrels less than 16" overall may be subject to NFA requirements. You are responsible for ensuring your build is compliant with state and federal laws. The Plan B (MEDIUM) specs are: Overall length: 2.300" Added length to barrel: ~1.8" (will qualify a barrel 14.5" or longer) From tip to taper: 1.5"
Note: If you select our Helix adjustment system for your barrel, your handguard length will be as follows:
18” barrel: 16.4” handguard
16” barrel: 14.4” handguard
14.5” barrel: 12.8” handguard
13.9” barrel: 12.2” handguard

If you send in your own gas block or select our fixed gas block for your barrel, the handguard length will be as follows, unless requested otherwise:
18” barrel: 17” handguard
16” barrel: 15” handguard
14.5” barrel: 13” handguard
13.9” barrel: 13” handguard
**These uppers come standard with full-size charging handle wings with gas deflection direction based on your selector setup. If you want something different send us an email or leave it in your order notes.
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Custom Build 6mm ARC Complete Upper

*URG orders may have a lead time of 4-6 months.

You’re well on your way to a better build with the Blackout Defense Dual Taper Lock (DTL) complete upper. The upper receiver and handguard are precision machined to achieve perfect alignment, giving a monolithic-like appearance. And with the alignment pins, you get a boost of structural integrity as well.

Dual Taper Lock system

Tapers are well known across industries to be one of the best self-centering mechanical fasteners for critical, continuous load, and loads under thermal expansion. The DTL system harnesses the power of taper locks to secure and center the barrel. 

The DTL system uses two tapers and two interlocking barrel nuts. The taper on our custom barrel extension mates with a taper on the I.D. of the first barrel nut; the second taper on the barrel profile mates with a taper on the I.D. of the second barrel nut.

This guarantees the centricity of the barrel and upper bores while stabilizing the chamber. The DTL design delivers a smoother shooting experience while prolonging barrel accuracy by providing rigidity and harmonic dampening right over the chamber.

It also provides an exceptionally rigid base for mounting the handguard that does not result in handguard deflection, while also substantially reducing POI shifts from impact and trauma to the rifle.

HELIX Gas Regulating Barrel System

Our Helix Gas Regulating Barrel System integrates an adjustable control knob directly onto the barrel, allowing precise gas flow tuning for suppressed or unsuppressed setups. Built for durability, it features a robust detent system, M42 cobalt steel adjustment rod, and high-temp spring, proven through 1,500 rounds of accelerated full-auto testing with zero failures.

Upper Receiver

The upper receiver is machined from Aerospace Grade Aluminum with enhanced walls for greater rigidity and structural integrity – all while keeping a low profile. It features two anti-rotation holes that align precisely with our handguard. What you’re left with is a monolithic-like style and design with an extremely robust upper/handguard combination.

The dust cover often goes unnoticed in an AR-15. Not to us. The dust cover is fully contained within the upper receiver. We don’t rely on a C-clip to keep everything in place. Instead, the dust cover hinge pin is held in place by the barrel nut, ensuring nothing comes loose during operation. Due to the variation of dust cover manufacturers and their loose tolerances, we’ve machined a very thin locking groove in the upper receiver. This allows the ball detent of the dust cover to “cut” its own channel in the upper receiver, ensuring a positive, audible lock up and exact alignment.

Handguard

Our handguard brings the full package together with its monolithic-like style when paired with our upper. Like to accessorize? Our DTL handguard gives you seven sides of M-LOK compatible mounting slots with a full-length Picatinny top rail. The hand deburring process we put our products through ensures a smooth finish throughout. And for style-conscious people, our barrel nut is hidden to provide an even cleaner look.

Barrel

Our cryogenically treated barrels start with premium 416-R stainless steel bars that are gun-drilled and reamed at standard production speeds in 5R rifling. The blanks are then fully stress-relieved and precision air gauged before profiling, threading, and chambering begin.

Our barrel profile features strategically placed linear expansion rings that control the heat growth of the barrel during heavy use. These unique design features, coupled with our adherence to improved machining tolerance standards, result in straighter bores, a superior finish, and improved accuracy.

Bolt Carrier Group

The Blackout Defense bolt carrier is manufactured from 8620 steel, while our shot-peened bolt is made from either 9310 or carpenter 158. The bolts are batch high pressure tested and individually magnetic particle inspected after heat-treat to ensure no microcracks.

Charging Handle

The ambidextrous design of the Stryker charging handle allows for multiple ways of use, no matter your shooting side or position.

*For safety reasons, we do not recommend using 6mm ARC cartridges that exceed the recommended Max Chamber pressure of 52,000 PSI. Doing will void your firearm’s warranty and can lead to injury and or death.

6MM ARC Semi-automatic Rifle Specific Loads


Features
  • Reinforced in critical areas
  • Monolithic-like appearance between upper and handguard
  • Alignment pins between upper and handguard
Specifications
Material:
Aerospace Grade Aluminum
Finish:
Blackout Black, Space Grey Cerakote, Flat Dark Earth Cerakote, Burnt Bronze Cerakote, Primordial Green Cerakote, Clear Anocoat
Compatibility:
Compatible with MILSPEC lower receivers. As of March 8, 2023 they are also compatible with SilencerCo and Radian lower receivers.


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