Brn16a1(R) 20" Complete Upper Receivers - Brn M16A1 Upper Receiver 20" Rifle Length, 1-12 Twist, Black
All Brownells upper receivers
Click to see full view
Brownells
Overview
The Brownells Brn16a1(R) Complete Upper Receiver features a 20-inch barrel and is designed specifically for the AR-15 platform, offering a rifle-length gas system for optimal reliability. With a 1:12 twist rate, it is well-suited for stabilizing lighter projectiles, making it ideal for a variety of 5.56 NATO ammunition. Builders often integrate this upper receiver into retro-style builds that pay homage to classic military configurations.
Specifications
Brn16a1(R) 20" Complete Upper Receivers - Brn M16A1 Upper Receiver 20" Rifle Length, 1-12 Twist, Black
Available Merchants(1)
Prices checked
Stock Alert
Build history on GunPartPicker
Builders on GunPartPicker first added the Brownells Brn16a1(R) 20" Complete Upper Receivers - Brn M16A1 Upper Receiver 20" Rifle Length, 1-12 Twist, Black to a build in February 2026.
It was out of stock everywhere we track for all of September 2026, and today the one retailer we track is out of stock. Listed prices start at $679.99 at Brownells for when it comes back.
Updated · from real builds on GunPartPicker · Prices checked · refreshed daily across 37 retailers
Not sure which upper receiver to pick?
We ranked every upper receiver by how often it shows up in real builds on GunPartPicker.
Read the guide: Most Popular AR-15 Upper Receivers →Check it against the live catalog:
Frequently Built With
Popular alongside upper receivers on GunPartPicker
Aero Precision M4E1 Complete Lower Receiver W/MOE SL Grip & SL-S Carbine Stock
Aero Precision AR-15 Breach Charging Handle Ambidextrous Small Levers
Geissele Automatics AR-15 SSA-E X Lightning Bow Trigger
Bravo Company M16 Bolt Carrier Group Black
Magpul AFG-2 Angled Fore Grip - Black
Magpul AR-15 MOE Stock Collapsible Mil-Spec Black
No reviews yet. Be the first to review this product!