Product Spotlight: Brownells BRN-180 13.9" & 14.5" Uppers

Brownells Gun Tech™ Caleb Savant gives us the inside scoop on the Brownells BRN-180® upper receivers with 13.9" and 14.5" barrels. The purpose of these seemingly odd lengths is to enable you to mount a specific muzzle device and keep the total barrel length to the 16" required by the National Firearms Act (NFA). If you do this, you must pin and weld the muzzle device permanently in place so that it becomes a part of the barrel. With a personal defense / home defense rifle, the shorter the better. These shorter barrels generate slightly reduced bullet velocities, but Caleb took his 13.9" BRN-180 to the range and got very respectable accuracy out to 500 yards.

 

NOTE: You can build a rifle with a barrel shorter than 16" IF you register it as an SBR (short-barreled rifle) with the ATF and pay for a $200 tax stamp. Check out our Quick Tip videos "SBRs & the NFA" and "How To Get an SBR" (links below) for full details on that process. You could also designate the gun as a pistol, which does not require ATF registration, but a 13.9" or 14.5" barrel is pretty long for a pistol. You'd probably want to use one of our BRN-180S® uppers with 10" and 10.5" barrels.

 

Unlike our other BRN-180 upper assemblies, these two do not come with a muzzle device, so you can choose the upper plus muzzle device combo that works for you and gets the barrel length up to the required 16". By "muzzle device" we mean a flash suppressor (flash hider) or a compensator. Caleb has some advice on putting a muzzle brake on these shorter barrels: DON'T. He explains why.

 

The standard A2 "bird cage" flash hider is too short for either of these barrels. On the 13.9" barrel, you'll need a muzzle device at least 2.7" long. That seems like more length than you need to hit 16", but remember the muzzle device overlaps the threaded portion of the muzzle (typically 0.6" long on 1/2"-28 threaded muzzles), so part of its length does not factor into meeting the 16" requirement. For the 14.5" barrel, you need a muzzle device at least 2.1" long.

 

Forward Controls Design offers a compensator / flash hider specifically for 13.9" barrels, and it even has a hole drilled in the bottom for the pin. Midwest Industries and SureFire also offer excellent compensators and flash hiders of the right length for the 13.9" BRN-180. Smith Enterprise and Precision Armament have devices that are little shorter than 2.7", but you can use a locknut as a spacer to position the device far enough forward.

 

Both uppers are in Gen 2 configuration, so they have the adjustable gas block with two settings, one for suppressed, the other for unsuppressed fire. The BRN-180 short-stroke piston operating system is contained entirely within the receiver, so no receiver extension (aka, buffer tube) is needed. You can put a folding stock on the lower receiver and shoot the rifle with that folding stock FOLDED. These uppers are fully compatible with standard "mil-spec" AR-15 lower receivers.

 

Caleb's rifle has the American Defense Manufacturing BRN-180 specific lower receiver with a Picatinny mount at the rear for the J-Mac Customs folding stock. It has a Smith Enterprise flash suppressor and a Brownells Match Precision Optic® rifle scope on top.