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Upgrade your Rifle with an A2 Upgrade Kit

Build Your A2 on Our Virtual Workbench.

Pieces of a Full-Length AR Build
Butt Stock & Buffer Tube Kit Upper Parts Kit Lower Parts Kit Upper Receiver Bolt Carrier Group (BCG) Gas Tube with Roll Pin Gas Block Muzzle Device Handguard Barrel

Butt Stock & Buffer Tube Kit

Butt Stock & Buffer Tube Kit:  ARchitect Complete Mil Spec Butt Stock & Buffer Tube Assembly

  • Polymer M4 Style Stock
  • Mil Spec Buffer Tube Assembly
  • Adjustable 6-Position Buffer Tube

“Fully Adjustable for Even Small-Frame Shooters & Youth.  Easily Removable Stock for Simple Upgrades.  Stock Upgrades Need to be Mil Spec Design, Not Commercial.”

Made in the USA

Upper Parts Kit

Upper Parts Kit:  ARchitect Complete Upper Parts Kit with Charging Handle

  • Dust Cover Assembly, Forward Assist Assembly & Charging Handle
  • Steel Components – Phosphated, Charging Handle – Hardcoat Black Anodized

“Mil Spec, Industry Standard Components.  Will Provide Years of Normal Use.”

Made in the USA

Lower Parts Kit

Lower Parts Kit:  ARchitect “ELG” Complete Lower Parts Kit with Fire Control Group

  • Includes All Necessary Components to Install Lower Receiver
  • All Components Black Phosphate Coated

“Enhanced Longitudinal Grinding on Hammer & Trigger For Crisp, Non-Gritty Trigger Pull.”

Made in the USA

Upper Receiver

Upper Receiver:  ARchitect Mil Spec Stripped Upper Receiver

  • Forged 7075-T6 Aluminum
  • M4 Feed Ramps
  • Hardcoat Black Anodized

“Perfect Entry-Level, Low Cost Option, Rugged, Durable & Functional.”

Made in the USA

Bolt Carrier Group (BCG)

Bolt Carrier Group (BCG):  ARchitect AR15 Black Nitride Bolt Carrier Group

  • M16 Profile 5.56/.223/.300/.350 Legend
  • Black Nitride Coated (Including Gas Key)

“Clean Crisp Look, Easy to Clean & Maintain.”

Made in the USA

Gas Tube with Roll Pin

Gas Tube with Roll Pin:  ARchitect Mid-Length Stainless Steel Gas Tube with Roll Pin

  •       Mil Spec
  • 304 Stainless Steel
  • Roll Pin Included

"Will Last for Years Under Normal Shooting Conditions"

Made in the USA

Gas Block

Gas Block:  Super Low Profile ARchitect 0.750” Diameter, Non-Adjustable Gas Block

  • Set Screw Style
  • Black Nitride Coated 4140 Steel

“Set Screw Style for Easy Installation & Alignment on our Pre-Dimpled Barrels, Black Nitride Coated for a Consistent Look with the Barrel”

Made in the USA

Muzzle Device

Three muzzle device options to choose from for your custom AR build. Choose between a Muzzle Brake, Flash Can, or a Flash Hider. Muzzle Brakes reduce recoil and muzzle rise but can be loud, Flash Cans direct blast and sound down-range, and Flash Hiders disperse any fireball and reduce muzzle side and are Industry Standard for most entry-level ARs.

Made in the USA


Two Lengths to Choose from for your custom AR build 13” or 15”. There is no functional difference between the different lengths, just a personal preference of the way it looks. The 13” leaves 2.5” of the barrel exposed and the 15” leaves 0.5”. Handguard comes in Black Anodize as the Industry Standard.

“The Easiest to Install System on the Market, No Timing & No Shims, Super Sturdy, Long 2” Barrel Nut for Rigidity, Lightweight, Machined To Magpul MLok Standards, Deep Satin Finish Black Anodize that Should be the Industry Standard.”

Made in the USA


Barrel: ARchitect .223 Wylde Gov’t Profile Mi- Length 1/8” Twist Barrel

  • 16” Length, Black Nitride Coated 4140 Steel
  • 750” Gas Block Seat
  • ½” x 28 Threaded for Muzzle Device
  • Mid-Length Gas System

“Can Shoot Either Platform Ammo (.223 or 5.56), Most Universal Twist Rate, Good From 50 to 77 Grain Bullets”

Made in the USA

How to Build Your AR Rifle with an A2 Upgrade

Select your desired handguard length and upgrade your handguard with the A2 upgrade kit and then select your optional add-ons if desired. 

Our build kits do not include a lower receiver. You must purchase a lower from a licensed FFL dealer and submit to the proper background checks to receive said lower receiver. Please be aware of all state and local laws as it pertains to building and owning an AR-15 rifle.

BYOAR makes no guarantees or assumptions about your ability to purchase or own an AR-15 lower.