Best AR 15 Parts And How To Identify Quality

AR 15 Parts – What You Need for Your Next Build

Building or putting together an AR 15 for yourself is now something a garage shop builder can do. There is a multitude of knowledge in the form of written guides and even video walkthroughs. Provided you are handy and have the tools and the proper AR 15 parts, building an AR 15 is relatively easy. It’s never been easier or more affordable to purchase the AR 15 parts needed to assemble a rifle that will last you for decades.

At Black Rifle Depot, we are proud to carry just about everything you need to get started on your build, excluding a registered lower. Not only do we have the AR 15 parts you need at a price that won’t break the bank, but Black Rifle Depot is also here for you at every step of the way to answer your questions. Not to mention that we started and run the world’s largest AR 15 Facebook Group, the AR 15 Builders Forum, be sure to check it out.

One of the most common questions from new builders is where to start. As such, we’ve compiled this article to overview the essential AR 15 parts and accessories you should consider for your first or next AR build. We’ll review AR 15 components like upper receivers, bolt carrier groups, muzzle devices, lower parts kits, and more.

AR 15 Lower Parts & AR 15 Lower Build Kits

At Black Rifle Depot, we firmly believe the overall quality of an AR 15 lower parts kit can increase the performance and reliability of your AR 15. That's why we proudly offer our BRD-branded Lower Parts Kit with high-quality components with a lifetime warranty.

Black Rifle Depot also carries a wide selection of AR 15 Lower Parts Kits from other top manufacturers in the industry, such as AERO Precision, Anderson Manufacturing, APOC Armory, CMMG, ODIN Works, and Strike Industries. Because we have decided only to carry products we believe in ourselves, no matter which product we choose, Black Rifle Depot backs all AR 15 Parts they offer with a lifetime warranty.

The AR 15 lower parts kits we sell at Black Rifle Depot are drop-in ready. Buying an affordable, high-quality AR-15 lower parts kit from a reputable source like Black Rifle Depot is a great way to save time, money and avoid hair-pulling moments as you work toward your completed AR-15 lower receiver.

Please look at our recent blog post to learn more about what to look for in an AR-15 lower parts kit. Choosing a Lower Parts Kit

AR 15 Upper Receivers

Black Rifle Depot carries a wide selection of AR 15 Upper Receivers from the top manufacturers in the industry. Black Rifle Depot offers AR 15 Upper Receivers from AERO Precision, Anderson Manufacturing, Faxon, and OEM unbranded AR 15 Upper Receivers with the trusted Cerro Forge mark.

Composing your upper receiver is relatively easy, provided you have the right tools. Search YouTube for walk-through videos.

As far as AR 15 parts you’ll need, Black Rifle Depot has you covered. If you’re buying a complete upper receiver assembly, you’ll want to get a quality upper receiver. Below we’ve listed some of the upper receivers we believe in.

Please be aware that Black Rifle Depot sells two kinds of upper receivers.

1. Assembled upper receivers (everything you need is installed)

2. Stripped upper receivers (missing forward assist and ejection port cover)

We’ll detail selections from both of these categories below.

AERO Precision Assembled Upper Receiver

For many builders, the Aero Precision upper receiver is a top choice regarding price and features. What’s also lovely about the Aero Precision Assembled Upper Receiver is that it is a name that is recognized far and wide as being high quality. The fit is super tight, meaning zero play is present with lowers from various manufacturers.

The Aero Precision Assembled Upper Receiver comes complete with both forward assist and dust cover installed. Machined from a 7075-T6 aluminum forging, the upper is then Type III Class 2 hard coat anodized and laser engraved with T-marks. These AERO Precision assembled uppers are compatible with AR16 and M16 parts and accessories.

Specifications:

• M4 feed ramps
• Anodized black
• Machined for .250” takedown/pivot pins
• Laser engraved T-marks
• Includes port door and forward assist
• Weight: 8.3 oz

BCMGUNFIGHTER Assembled Upper Receiver

Bravo Company's BCMGUNFIGHTER Assembled Upper receiver has one of the tightest tolerances of any forged AR-15 Upper receiver. The BCMGUNFIGHTER Assembled Upper Receiver is machined from 7075-T6 aluminum and has a type 3 hard coat anodized flat finish for corrosion resistance. Each BCMGUNFIGHTER Assembled Upper receiver comes with laser engraved T-Markings and is assembled with forward assist and ejection port cover.

Specifications:

• Laser engraved T-markings
• No BCM logo etched on the rear of the rail
• Marked BCM4 over the gas tube port
• 7075-T6 aluminum
• Factory-assembled forward assist, and ejection port cover
• Hard coat Type III, Class 2 anodized
• Dry film lube on interior bore per MIL-SPEC
• Made in the U.S.A.
• NOTE: Please use a heat gun or hair dryer to warm up the threaded bore of the receiver if the barrel extension is too tight.
• OEM Assembled Upper Receiver
• Specifications:
• M4 feed ramps
• Anodized black
• Machined for .250” takedown/pivot pins
• Includes port door and forward assist
• Weight: 8.3 oz
• Cerro Forge Mark

Faxon Firearms Forged 7075-T6 Upper Receiver - Anodized

If you’re planning to Cerakote, this is perhaps the upper receiver. The reason is that the T-marks on this upper receiver are truly engraved versus laser engraved; this means they will still appear when covered.

Specifications:

• Material: 7075-T6 Forged Aluminum
• Finish: Type III Hard Coat Anodizing
• Caliber Compatibility: All intermediate cartridges. (.458 and large bore rounds may not function in the intermediate upper.)
• T-Marks: Engraved
• Weight: .43 Lbs. (6.88 Ounces)

The following category of upper receivers is “stripped,” meaning you’ll need to do a bit more work on them to get them up and running, including installing the ejection port cover and the forward assist, which can be slightly challenging to the new builder, although it is certainly doable.

If you’re not afraid of more work, you might want to consider purchasing a stripped upper receiver.

Anderson Manufacturing Stripped Upper Receiver

Anderson Manufacturing stripped upper receivers are forged from 7075-T6 aluminum forgings. Each Anderson Manufacturing stripped upper receiver comes with M-4 feed ramps and is type III hard coat anodized black for corrosion resistance. The top is cut with a Picatinny rail system and is compatible with most accessories.

Regarding budget-friendly upper receivers that you can trust, I’ve always enjoyed the Anderson Manufacturing stripped upper receiver. The quality of this upper is awe-inspiring for the price you're paying.

Specifications:

• 7075-T6 aluminum
• M4 feed ramps
• MIL-SPEC Type III hard coat anodized black
• Picatinny rail

OEM Stripped Upper Receiver

Black Rifle Depot's AR-15 Stripped Upper Receiver is built to MIL-SPEC. Crafted from a 7075-T6 aluminum forging and machined with M4 feed ramps. Forge marks vary due to availability.

NOTE: Forward assist, and ejection port cover is sold separately.

Specifications:

• 7075-T6 Forged Aluminum
• Type 3 Hard Coat Anodized
• M4 Feed Ramps
• Forward Assist & Dust Cover Ready
• Receiver Forge Marks Vary

Black Rifle Depot's Stripped Upper Receiver With T-Marks

Black Rifle Depot's AR-15 Stripped Upper Receiver is built to MIL-SPEC. Crafted from a 7075-T6 aluminum forging and machined with M4 feed ramps. Forge marks vary due to availability.

Specifications:

• Type 3 Hard Coat Anodized
• Forged 7075-T6 Aluminum
• Dust Cover - Forward Assist Ready
• M4 Feed Ramps
• Hard Coat Anodized
• Proudly Made in the U.S.A
• Lifetime Warranty

AR 15 Barrels

Now that you’ve selected your upper receiver, you need a barrel. If you’re looking for an AR-15 barrel for your next custom build, Black Rifle Depot has you covered.

Black Rifle Depot has a wide selection of AR-15 barrels from some of the top manufacturers in the industry, such as AERO Precision, APOC Armory, Ballistic Advantage, Faxon, Odin Works, and unbranded OEM. No matter what brand you go with, Black Rifle Depot offers a lifetime warranty on all our barrels.

APOC Armory Barrels

APOC Armory premium cold hammer forged upper collection was created with the serious shooter in mind. We started with a 7075-T6 forged A3 upper receiver with machined t-marks, forward assist, and dust cover. Each upper assembly comes with one of our QpQ black nitride cold hammer forged barrels made in California.

Even the steel .750 low profile gas block and muzzle devices are black nitride treated for durability and a matching jet-black finish and backed with a lifetime warranty against defects in product or workmanship along with sub moa guarantee (using factory match grade ammo).

We highly recommend these barrels and think they’re an excellent fit for a broad spectrum of shooters.

Faxon Firearms 16″ Government Profile 5.56 NATO Mid-Length 4150 Black Nitride Barrel

Faxon makes outstanding barrels...you can learn more about them via this video:

If you're looking for a basic barrel that is high quality and won't break the bank, this is certainly one to consider.

Specifications:

• Barrel Material: 4150
• Barrel Type: Button Rifled
• Barrel Caliber: 5.56 NATO
• Barrel Twist: 1:8
• Barrel Length: 16″
• Barrel Profile: Gov’t/SOCOM
• Barrel Gas System: Mid Length
• Inside Finish: QPQ Nitride
• Outside Finish: QPQ Nitride
• Muzzle Thread: 1/2-28 TPI (Threads Per Inch)
• Gas Block Diameter: .750″
• Gas Block Journal Length: 1.9″
• Barrel Extension: M4
• Weight: 1.65lbs
• Magnetic Particle Inspected
• 11-degree Target Crown

Bear Creek Arsenal 16" .300 Black Out Barrel

Are you looking for a barrel for hunting deer? A 16" 300 Blackout barrel like this is a great idea, especially when combined with 110-grain hunting ammo from somewhere like Barnes. It's a devastating combination; we've had nothing but great feedback on this particular barrel.

Specifications:

• 1:10 Twist
• Black Nitride Treated
• 4150 CMV Barrel Steel
• Pistol Length Gas System
• Thread: 5/8-24
• Lifetime Warranty

16" 5.56 Barrel Bundle

As you know, you'll need more than just a barrel to build a completed AR-15 upper. There are other AR-15 parts that you'll need, including AR-15 parts like a muzzle device, gas block, and gas tube. We've compiled all of that, along with a great Ballistic Advantage barrel, in this Barrel Bundle.

Specifications:

• Ballistic Advantage 16" 5.56 Modern Series (QpQ Nitride)
• A2 Bird Cage muzzle device W/Crush Washer
• .750 Steel Gas Block (QpQ Nitride)
• Stainless Steel Mid Length Gas Tube

AR 15 Complete Upper Assemblies

If building an upper receiver assembly sounds daunting, we don’t blame you. One way to approach a new build is to avoid the hassle of purchasing a complete upper receiver assembly. Drop it onto your completed AR-15 lower, and you’re ready to go.

Whether you are choosing one of our in-house OEM brand AR-15 Uppers or one of the many name brands we carry, Black Rifle Depot has you covered. Black Rifle Depot has a wide selection of AR 15 Complete Uppers from manufacturers such as AERO Precision, APOC Armory, Dirty Bird Industries, and unbranded OEM. No matter what AR-15 Complete Upper you choose, we offer a lifetime warranty on all products we sell.

APOC Armory Complete Upper Assemblies

APOC Armory AR-15 Complete Uppers are designed with the serious shooter in mind. APOC Armory specializes in quality AR-15 Uppers using only top-tier AR-15 parts, such as our famous cold hammer forged AR-15 barrels. Each AR-15 Upper is assembled and inspected by our APOC Armory staff and has a lifetime warranty. All APOC Armory AR-15 Complete Uppers have a 1" MOA Guarantee for the barrel's life.

APOC Armory Elite 16" 5.56 Complete Upper

Specifications:

• 16" 5.56 1:7 QpQ Nitride
• Elite Muzzle Brake
• Mid Length of Gas System
• .750 APOC Armory Low Profile Gas Block
• 7075-T6 Forged Custom Receiver
• 15" Slim Line Free Float M LOK Hand Guard
• 4 LBS 4.6OZ Complete
• Proudly Made In The U.S.A.
• 1" MOA Guarantee
• Lifetime warranty

APOC Armory Patriot 16" 5.56 1:7 Complete Upper

Our top-selling complete upper assembly for the AR 15, the Patriot, is expertly assembled and fitted with premium-quality AR 15 parts. It's an upper configured for the builder who wants an accurate shooting rifle that performs reliably in various situations.

The Patriot is built to last and guaranteed to be free from defects in materials and craftsmanship for the lifetime of the upper assembly.

Specifications:

• 16" Government Profile Barrel With M4 Feed Ramps
• 1:7 twist
• Black Nitride A2 Muzzle Brake
• Black Nitride .750 Steel Low Profile gas block
• Mid Length of Gas System
• 7075-T6 Forged Upper
• Available Black Nitride or Nickel Boron MPI Tested BCG
• 12" Free Float Key Mod Rail (Cerakote)
• Standard Charging Handle
• Proudly Made in The U.S.A
• Lifetime Warranty

APOC Armory 16" .223 Wylde CHF Complete Upper Titan

APOC Armory Titan upper assembly collection comes standard with our black nitride barrel. These uppers use high-quality AR-15 parts assembled on a forged 7075-T6 anodized receiver with t-marks.

We went with an ultra-lightweight 12" free float M-LOK hand guard. The gas block and the muzzle device are black nitride treated to match the barrel.

You can choose black nitride or premium nickel boron bolt carrier group with an extended latch charging handle. These uppers have a 1" MOA guarantee and an unconditional lifetime warranty on all parts and labor.

Specifications:

• 16" .223 Wylde 1:7 Twist Cold Hammer Forged
• 4150 CMV Barrel Steel
• Black Nitride Treated
• Mid Length of Gas System
• APOC Armory Tunable Gas Block
• Competition Muzzle brake
• 12" Free Float M-LOK
• 7075-T6 Forged Anodized Upper Receiver with FA/DC
• Extended Latch Charging Handle (With BCG Purchase)
• 1" MOA Guarantee
• Lifetime Warranty

Other Complete Upper Assemblies

Dirty Bird 16" Govt Mid 556 M-LOK Complete Upper

This Dirty Bird Industries Complete Upper features a Black Nitride 16" Sub-MOA Government Profile barrel chambered in 5.56 with a 1:7 twist. Built on a top-tier t-marked Forged Upper Receiver and finished with Dirty Bird's 15" SMRS M-LOK Handguard available in several color options.

No corners are cut when manufacturing these complete uppers or the AR-15 parts they contain. All barrels are dimpled and cold-blued; use a black nitride 4140 steel gas block and a stainless-steel gas tube.

The gas block set screws feature knurled cone tops and are installed using blue Loctite, ensuring that no amount of firing will cause the set screws to come loose but can still be removed for servicing.

**Does NOT include BCG or Charging Handle

• Made in the USA - Backed by Dirty Bird Industries' Limited Lifetime Warranty
• Specifications:
• Barrel Chambered in 5.56 (will also function with .223)
• 16" Government Profile w/ 1:7 Twist
• Mid-Length Gas System
• Black Nitride Finish
• High Pressure Tested and Magnetic Particle Inspected
• Sub-MOA Guarantee

Dirty Bird M16A1 Retro Complete Upper

The Dirty Bird Industries M16A1 20″ 5.56 Retro Upper Assembly is the next iteration of DBI’s popular Complete Uppers. Dirty Bird Industries has sourced some of the finest parts in

the industry to make sure that this complete upper is not only a great throwback build and aesthetically accurate but also performs flawlessly in the field by taking advantage of modern enhancements to the platform.

Notable enhancements include a 1:9 twist instead of 1:12, which will stabilize more bullet weights, M4 style feed ramps for improved reliability, and a black class 3 type 2 anodizing to match most modern mil-spec lower receivers.

Specifications:

• Chambered in 5.56
• 1:9 Twist Rate
• Button Rifled
• A2 Front Sight Base w/ Front Sight Post Installed
• 7075-T6 Forged Aluminum
• Factory Installed Teardrop Forward Assist & Dust Cover
• Factory Installed Dual Aperture Rear Sight
• Integrated M4 Feed Ramps
• Fully Compatible with any Mil-Spec Lower Receiver

AR 15 Bolt Carrier Groups

Black Rifle Depot carries a wide selection of AR 15 Bolt Carrier Groups for your next custom build. We offer AR 15 Bolt Carrier Groups from manufacturers such as AERO Precision, APOC Armory, and Odin Works, as well as unbranded AR 15 Bolt Carrier from Toolcraft, Inc. Black Rifle Depot stands behind our products and offers a lifetime warranty on all AR 15 Bolt Carriers that we carry.

APOC Armory Black Nitride Bolt Carrier Group 5.56/.223

The QPQ (Quench Polish Quench) process is an advanced Black Nitriding process that augments the standard Nu-Tride process. Enhancing corrosion resistance involves a secondary polishing operation, followed by re-oxidation to produce a lustrous black finish and case hardening of the steel. Tests show significantly reduced wear to components subjected to black nitride over standard parkerizing methods.

Specifications:

• 5.56/.223/.300 Blackout
• Full Auto Capable
• 9310 MPI and HPT Tested Bolt
• Case Hardened 8620 Carrier
• 4130 Gas Key
• Grade 8 Hardware with Proper Staking
• Gas Key Sealed with Permatex No.3
• 8740 Hard Chrome Firing Pin
• Black Nitride Treated for Reduced Friction And Increased Longevity
• Proudly Made in the U.S.A

AERO Precision Black Nitride Bolt Carrier Group

Specifications:

• M16-cut carrier
• Machined from 8620 steel
• Carrier has forward assist serrations
• Black Nitride Finish - advanced lower friction coating that minimizes the need for lubricants and cleaning
• Properly staked gas key
• 5.56 Bolt is machined from Carpenter 158 tool steel
• Shot peened
• HPT tested/MPI marked
• Black O-ring inserts on the extractor
• High-quality BCG

OEM Black Nitride .223/5.56/300BLK M16 Profile Bolt Carrier Group

Specifications:

• 5.56/.223/.300 Black Out
• Full Auto Capable
• 9310 MPI and HPT Tested Bolt
• Case Hardened 8620 Carrier
• 4130 Gas Key
• Grade 8 Hardware with Proper Staking
• Gas Key Sealed with Permatex No.3
• 8740 Hard Chrome Firing Pin
• Black Nitride Treated for Reduced Friction and Increased Longevity
• Proudly Made in the U.S.A

Toolcraft Black Nitride .223/5.56/300BLK M16 Profile Bolt Carrier Group

Specifications:

• 5.56/.223/.300 Blackout
• Full Auto Capable
• 9310 MPI and HPT Tested Bolt
• Case Hardened 8620 Carrier
• 4130 Gas Key
• Grade 8 Hardware with Proper Staking
• Gas Key Sealed with Permatex No.3
• 8740 Hard Chrome Firing Pin
• Black Nitride Treated for Reduced Friction and Increased Longevity
• Proudly Made in the U.S.A
• Unconditional Lifetime Warranty

AR 15 Charging Handle

Choosing the suitable AR 15 Charging Handle is a tedious task. Black Rifle Depot offers a wide selection of AR 15 Charging Handles from different manufacturers making the task that much easier, with various designs from manufacturers such as AERO Precision, APOC Armory, BCM, Fortis, Strike Industries, Odin Works, and unbranded OEM.

AR 15 Gas System

AR 15 gas blocks and 15 gas tubes come in different materials and finishes, from Black Nitride to Stainless Steel. Black Rifle Depot offers a variety of manufacturers, and depending on your custom build, you may be interested in an upgraded Adjustable Gas Block from ODIN Works or APOC Armory. No matter what your choice Black Rifle Depot covers all AR-15 gas blocks and gas tubes with a lifetime warranty.

AR 15 Handguards

Black Rifle Depot offers a wide selection of AR 15 Handguards from Quad Handguards to M-lok from AERO Precision, APOC Armory, Dirty Bird Industries, ERGO, ODIN Works, and unbranded OEM.

AERO Precision AR15 Quantum M-LOK Hand Guard

AERO Precision Quantum Series M-LOK Handguards minimize bulk while providing an adaptive free-float design that is big on features. With multiple mounting options, this affordable, rigid system can adapt to any mission. Machined to exact dimensions from 6061-T6 aluminum, it is the perfect handguard for your next AR-15 build.

Specifications:

• 12" Length
• Designed to work with our M4E1 Upper Receiver
• One-piece free float design
• Removable 4-slot Picatinny rail section for front sight
• Built-in anti-rotation tabs
• eight mounting surfaces for M-LOK accessories
• 1.78" inside diameter fits most muzzle devices and 1.5" suppressors
• Compatible with low-profile gas blocks
• Made in the USA

Black Rifle Depot Free Float Lightweight M-Lok Handguard

Specifications:

• 6061-T6 Aluminum
• Type 3 Hard Coat Anodized
• Clamp on design
• Includes Steel Barrel Nut And Set screws
• Lightweight Design
• 13 Oz Including Barrel Nut
• Lifetime warranty

Bravo Company 13" Alpha Keymod Handguard

Also available in 15 and 17", the Bravo Company's BCM KMR ALPHA 13" KeyMod Free Float Handguard" is manufactured from aluminum that is lightweight yet durable. It also features a proprietary patent pending mounting" indexing and lock up system that mitigates noon rail movement under heat generated from the barrel nut. The inner diameter is 1.3", and the outside is 1.5" flat to flat.

The handguard flares forward (towards muzzle end) at the 3 and 9 O'clock positions approximately 1/4", and the actual length when measured to flare is 13.4.

Dirty Bird AR-15 SMRS Handguard - Slim M-LOK Rail System

The SMRS (Slim M-LOK Rail System) by Dirty Bird Industries is a high-quality, feature-packed M-LOK handguard designed for AR-15 platform rifles and pistols. When designing this handguard, the team started from a basic set of requirements: The handguard must be rugged, versatile, practical, and have a straightforward installation.

Specifications:

• Machined from aircraft grade 6061-T6 aluminum extrusions.
• Anti-rotation tabs.
• Type 3 hard anodizing or Cerakote™ sprayed at one mil thickness per spec.
• M-LOK attachment slots on all sides (except the top)
• 1913 Picatinny top rail with shaved and beveled center section.
• Raised QD attachment points at the 3 and 9 o'clock positions.
• Snag-free design with smooth, uniform octagonal surface ideal for accessory attachment or application of specialty coatings or patterns.
• No extraneous cuts in the aluminum simply for weight savings or enhanced visual appearance.
• Aircraft Grade aluminum barrel nut.
• Compatible with most known low-profile gas blocks.
• Straight Forward Installation

UTG Hand Guard - 15" Super Slim

The UTG Pro model 4/15 rifle 15" super slim free float handguard has a proprietary attachment design and an extremely compact profile. It is super lightweight with a rail at noon, forming a continuous picatinny top section. It includes three user-detachable 2-slot rail sections.

Specifications:

• Integral anti-rotation tab for sock-solid locking
• Accommodates low-profile gas block
• Ergonomic slim tubular profile for most positive handling
• Trinity Force KMX15 Free Float 15" Handguard
• Specifications:
• KMX Series features a Key Mod Compatible mounting system
• Free Float Hand Guard
• Durable 6061-T6 Aluminum Construction
• FREELOK Barrel Nut and Clamping System
• Hard Coat Anodized Finish
• Two Quick Detach Sockets
• Designed to be used with pistol length, carbine length, mid-length, or Mil-Spec M16 rifle-length gas systems.

AR 15 Muzzle Devices

To top off your new barrel, you’ll want to ensure you have a muzzle device. A muzzle device is a functional add-on attached to the end of your AR 15 barrel. At Black Rifle Depot, we have various flash hiders, muzzle brakes, and more.

AR 15 Parts from Black Rifle Depot

In conclusion, no matter which AR15 parts you choose for your carbine or pistol, any of the above will provide you with a strong and reliable starting point for your new AR build. Regardless of your choice, know we have you covered at Black Rifle Depot. We also understand that these sorts of topics can be confusing for a beginner. We hope this blog helps, but if not, please know we’re here to help and walk you through your purchase.