Aero Precision Apra600006C Mod 4 Handguard 9.1 Blk

The Aero Precision MOD 4 handguard is a precision-engineered rail system built for AR-15 shooters who demand stiffness, reliability, and versatility without compromise. Machined from 6061-T6 aluminum and secured with a steel barrel nut, this handguard is designed to minimize deflection under load and reduce point-of-impact shift—especially critical if you're running an infrared laser aiming device. Whether you're setting up a precision rifle, a tactical build, or a hunting AR, the MOD 4 delivers the rigid platform you need for consistent performance.

Installation is straightforward: the barrel nut requires no timing, and its lug pattern matches mil-spec castle nuts, so you won't need specialty tools. Two anti-rotation set screws provide redundancy and ensure a rock-solid fit, even with third-party upper receivers. The handguard ships with the barrel nut and mounting hardware, everything you need to get it on the gun.

Customization is built in. A full-length 7-sided M-LOK interface runs the length of the rail, letting you mount lights, grips, vertical foregrips, or other accessories exactly where you want them. The four steel-reinforced quick-disconnect sockets won't wear out with repeated use—a detail that matters if you rotate slings between rifles or run your gun hard. Internal diameter of 1.2" accommodates low-profile gas blocks, keeping your setup compact without sacrificing function.

The MOD 4 plays well with Aero's M4E1 Threaded Upper Receivers and PRO series components, but it's also compatible with any mil-spec AR-15 upper receiver, giving you flexibility in your build choices.

Key Features

• 6061-T6 aluminum construction engineered for stiffness and minimal deflection
• Steel barrel nut reduces point-of-impact shift under load
• Full-length 7-sided M-LOK interface for unlimited accessory mounting
• Four steel-reinforced quick-disconnect sockets for durable sling attachment
• Two anti-rotation set screws for secure, repeatable fit
• No timing required at barrel nut; uses standard mil-spec lug pattern
• Compatible with low-profile gas blocks
• Barrel nut and mounting hardware included

Specifications

Platform	AR-15 Series
Series	MOD 4
Material	Machined 6061-T6 Aluminum
Attachment Type	M-LOK
Internal Diameter	1.2"
Available Lengths	10.6", 11.4", 12.7", 13.5", 15"
Weight (10.6")	14.78 oz
Weight (11.4")	15.06 oz
Weight (12.7")	16.12 oz
Weight (13.5")	16.75 oz
Weight (15")	17.73 oz
Barrel Nut Torque Spec	55 ± 5 in-lbs
Included Components	MOD 4 Handguard, Steel Barrel Nut, Mounting Hardware

Frequently Asked Questions

What AR-15 upper receivers is this handguard compatible with?

The MOD 4 handguard is designed to pair seamlessly with Aero Precision's M4E1 Threaded Upper Receivers and PRO series components. It's also fully compatible with any mil-spec AR-15 upper receiver, giving you broad compatibility across different builds and manufacturers.

Do I need special tools to install it?

No. The barrel nut requires no timing and uses a lug pattern that matches standard mil-spec castle nuts, so you can install it with common tools. The handguard comes with the barrel nut and all mounting hardware you'll need.

Can I use a low-profile gas block with this handguard?

Yes. The MOD 4 is designed to accommodate low-profile gas blocks, allowing you to maintain a clean, compact profile on your upper receiver.

What's included in the box?

Each MOD 4 handguard comes with the rail itself, the steel barrel nut, and mounting hardware. You'll have everything needed to install it on your upper receiver.