Midwest Industries Ar-15 Brn-180 Side-Folding Trapdoor Stock Black

The Midwest Industries AR-15 BRN-180 side-folding trapdoor stock brings classic AR-180 lines and genuine utility to your modern rifle platform. Built around a 1913 Picatinny rail interface, this folding stock trades length for packability without sacrificing a proper cheek weld—the 13.75" length of pull mirrors the original AR-180 rifle geometry. Heavy-duty construction centers on 4140 heat-treated steel hinges and a full-length locking lug that locks positively in both open and folded positions, while the mag-phosphate finish protects steel parts from corrosion. Right- or left-folding configuration is your choice.

What sets this stock apart is the hinged trapdoor buttplate and genuine internal storage: 8 inches of clear length accommodates a complete AR-15 cleaning kit with a three-piece steel rod, and the 1.050" interior width fits standard 1.0" diameter oil bottles. The heavily fiber-reinforced polymer body weighs just 11.3 ounces, while the hinge assembly adds 6.9 ounces—total package comes in at 18.2 ounces. The spring-loaded plunger opens with a bullet point or small tool; contents aren't waterproof from a hard dunking, but a zip-lock bag keeps your maintenance kit dry inside. Folded, the stock adds 0.75 inches to your overall length. Installation hardware and allen wrenches are included.

This is the stock for shooters who value compact storage and field-proven design: hunters running shorter-barreled uppers, tactical rifle enthusiasts, or anyone who runs out of truck space. The generous buttplate area delivers soft felt recoil absorption, and the locking mechanism leaves zero wobble in either position. It's a no-nonsense upgrade that works as hard as you do.

Key Features

• Heavy-duty 4140 heat-treated steel hinges with positive lock in both positions
• Full-length locking lug for maximum strength and zero play
• Side-folding design (configurable right or left) reduces overall length by 0.75" when collapsed
• Original AR-180 styling with modern utility—13.75" length of pull
• Hinged trapdoor buttplate with ample storage for cleaning kit and maintenance supplies
• Fits firearms with 1913 Picatinny rail interface
• Mag-phosphate finished steel parts resist corrosion
• Installation hardware and allen wrenches included

Specifications

Frequently Asked Questions

What AR-15 platforms does this side-folding stock fit?

The BRN-180 trapdoor stock attaches to any AR-15 or similar platform equipped with a 1913 Picatinny rail. Installation hardware and allen wrenches are provided.

Can I configure this stock to fold left or right?

Yes. The steel hinges can be set up to allow the stock to fold either left or right, depending on your preference and mounting position.

What fits inside the trapdoor storage compartment?

The internal compartment measures 8 inches long and 1.050 inches wide, easily accommodating a complete AR-15 cleaning kit with three-piece steel cleaning rod. The width also fits standard 1.0-inch diameter oil bottles. The stock is not watertight, so use a plastic bag if you need water protection.

How much does this stock weigh?

The polymer stock weighs 11.3 ounces; the steel hinge assembly adds 6.9 ounces, for a total complete assembly weight of 18.2 ounces.