Brand: Sig Sauer
Model: M400 Forged
Platform: AR-15
Caliber: 5.56 NATO
Gas System: Mid-Length / Direct Impingement
Barrel Length: 16"
Barrel Description: Cold Hammer Forged
Barrel Finish: Black
Capacity: 30rds
Twist Rate: 1:7
Muzzle Thread: 1/2 x 28
Muzzle Device: A2 Flash Hider
Stock Description: 6 Position MAGPUL SL-K Stock
Stock Material: Polymer
Grip Description: AR Pistol Grip
Grip Material: Polymer
Furniture Finish: Black
Upper Receiver Material: 7075-T6 Aluminum
Upper Receiver Finish: FDE
Lower Receiver Material: 7075-T6 Aluminum
Lower Receiver Finish: FDE
FCG: Triggertech Two-Stage Flat
Rail Description: 15"
Rail Material: Aluminum
Rail Finish: FDE
Attachment Style: M-LOK
Safety: Ambidextrous Safety
Bolt Carrier Group: Yes
Charging Handle: Ambidextrous Charging Handle
OAL: 35.5"
Weight: 6.8 lbs
Includes: Sig Romeo MSR Gen II w/2MOA Red Dot Sight

Features

The SIG Sauer M400 FORGE Series is built on a legacy of proven accuracy and reliability, delivering a modern 5.56 NATO platform designed for consistent performance. At its core is a cold hammer forged barrel, providing long-term durability and precision, paired with a mid-length gas system for smooth, balanced operation. The rifle is equipped with a TriggerTech 3.5-pound two-stage flat blade duty trigger, offering a crisp and consistent break for enhanced control and shot placement.

Outfitted for versatility, the M400 FORGE includes a ROMEO-MSR Gen II red dot with a 2 MOA reticle for rapid target acquisition. An ambidextrous charging handle enhances usability for a wide range of shooters, while the lightweight aluminum handguard provides strength and supports accessory mounting. Designed for adaptability and reliability, this rifle offers a refined combination of premium components and practical performance.

The SIG ROMEO-MSR Gen II red dot sight is a compact and durable optic designed for fast target acquisition and reliable performance across a variety of shooting applications. Featuring a ruggedized industrial design and a parallax-free optical system, it enhances accuracy and speed in both close and intermediate engagements. A rotary illumination dial provides multiple brightness settings, including daylight and night vision-compatible options, while a CR2032 battery delivers extended runtime. With dependable waterproof and fog-proof construction, this optic maintains clarity and functionality in demanding conditions.

Report incorrect product description

Reviews

Q & A

Retail Stock

Compliance

Shipping Restrictions

It is the customer’s responsibility for understanding state laws regarding all purchases made. For a comprehensive list of all Shipping Restrictions, please refer to our Shipping Restrictions By State Page found Here.

All NFA Rules Apply

These items are controlled by the U.S. Government and authorized for export only to the country of ultimate destination for use by the ultimate consignee or end-user(s) herein identified. They may not be resold, transferred, or otherwise disposed of, to any other country or to any person other than the authorized ultimate consignee or end-user(s), either in their original form or after being incorporated into other items, without first obtaining approval from the U.S. government or as otherwise authorized by U.S. law and regulations.

Magazines will be removed from firearms when shipping to states with magazine capacity restrictions.

California 10+ Round Magazine Buyers: PSA values your freedom and constitutional rights above all else. However, PSA will not accept new orders nor will ship any order until the Ninth Circuit Federal Court of Appeals mandate becomes finalized. Once this mandate is finalized, we will start accepting new orders and ship 10+ round magazines to California Customers.

WARNING: Handling firearms or firearms parts can expose you to lead and other petroleum products known to the State of California to cause cancer, birth defects, or other reproductive harm. Wash hands thoroughly after handling. For more information go to www.p65warnings.ca.gov (CA Health and Safety Code Section 25249.6).