Brn-4 Piston Upper Receiver Kits - Brn-4 16'''' Upper Receiver KIT W/ Medium Profile Barrel
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Overview
The Brn-4 Piston Upper Receiver Kit from Brownells is a complete assembly designed for the AR-15 platform, featuring a 16-inch medium profile barrel that offers versatility for various shooting applications. This upper receiver kit operates in multiple calibers, making it a flexible choice for builders looking to customize their firearms. You'll often find this kit in builds that prioritize reliability and performance in both tactical and recreational settings.
Specifications
Brn-4 Piston Upper Receiver Kits - Brn-4 16'''' Upper Receiver KIT W/ Medium Profile Barrel
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Build history on GunPartPicker
Builders have been adding the Brownells Brn-4 Piston Upper Receiver Kits - Brn-4 16'''' Upper Receiver KIT W/ Medium Profile Barrel to their builds on GunPartPicker since June 2026. All time, it ranks #477 of the 1,682 upper receivers builders have added.
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 $1,839.99 at Brownells for when it comes back.
Updated · from real builds on GunPartPicker · Prices checked · refreshed daily across 37 retailers
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