SIG M400 FORGE MOSS GREEN 5.56 NATO 30 RDS RIFLE

SIG Sauer M400 FORGE is a semi-automatic 5.56 NATO rifle based on the AR-15 platform, featuring a 406 mm cold-hammer-forged barrel, mid-length gas system, and a free-floating aluminum M-LOK handguard. The set, finished in Moss Green Cerakote, includes a TriggerTech 1.59 kg two-stage trigger, ROMEO-MSR Gen II 2 MOA red dot sight, and one 30-round polymer magazine.

Suitable for use in

• Sport target shooting

• Dynamic shooting

• Range training

• As a base platform for IPSC Rifle or other suitable competition classes

• Practicing AR-15 platform handling

• Shooting with an optical sight

• Users who require an adjustable stock

• Right- and left-handed shooters

• Customization with M-LOK accessories

• Shooters who prefer a semi-automatic rifle in 5.56 NATO caliber

• Users seeking a factory-installed quality trigger and red dot sight

Why choose the SIG Sauer M400 FORGE?

• Popular AR-15 platform

• Caliber 5.56 NATO

• 406 mm or 16-inch barrel

• Cold-hammer-forged steel barrel

• Fast 1:7" twist rate

• Mid-length gas system

• Direct impingement gas system

• Two-stage TriggerTech trigger

• Trigger pull weight approximately 1.59 kg

• Flat-faced trigger

• Includes ROMEO-MSR Gen II red dot sight

• 2 MOA dot

• Full-length free-floating aluminum M-LOK handguard

• Full-length Picatinny rail on top of the handguard

• Ambidextrous charging handle

• Ambidextrous safety selector

• Six-position Magpul SL-K telescoping stock

• Pistol grip with a reduced angle

• 1/2"-28 muzzle thread

• A2-type flash hider

• Moss Green Cerakote finish

Technical specifications

• Manufacturer: SIG Sauer

• Model: M400 FORGE

• Product type: semi-automatic rifle

• Platform: AR-15

• Caliber: 5.56 NATO

• Bolt system: rotating bolt

• Operating mode: semi-automatic

• Gas system: mid-length direct impingement

• Adjustable gas system: not specified by manufacturer

• Barrel length: 406 mm / 16"

• Barrel material: cold-hammer-forged steel

• Twist rate: 1:7"

• Muzzle thread: 1/2"-28

• Thread shoulder: 90°

• Muzzle device: A2 Birdcage flash hider

• Trigger: TriggerTech Duty

• Trigger system: two-stage

• Trigger shape: flat

• Trigger pull weight: approximately 1.59 kg / 3.5 lb

• Safety selector: ambidextrous

• Charging handle: ambidextrous

• Stock: Magpul SL-K

• Stock adjustment: six positions

• Grip: reduced angle

• Handguard: free-floating aluminum M-LOK handguard

• Handguard finish: Moss Green Cerakote

• Accessory mounts: M-LOK

• Top optic rail: full-length Picatinny

• Included sight: SIG Sauer ROMEO-MSR Gen II

• Sight type: closed-body red dot sight

• Dot size: 2 MOA

• Overall length with stock extended: approximately 902 mm

• Length with stock collapsed: approximately 819 mm

• Width: approximately 69 mm

• Height with included sight: approximately 239 mm

• Weight: approximately 3.08 kg

• Magazine type: AR-15 polymer magazine

• Magazine capacity: 30 rounds

• Number of magazines included: 1

• Color: Moss Green

• Rifle finish: Moss Green Cerakote

Set includes

• SIG Sauer M400 FORGE 5.56 NATO rifle

• SIG Sauer ROMEO-MSR Gen II 2 MOA red dot sight

• One 30-round AR-15 polymer magazine

• Magpul SL-K six-position telescoping stock

• A2 Birdcage flash hider

• Manufacturer documentation

• Factory transport case or packaging according to the delivery set

Please check with the seller for the specific delivery set, magazine, sight mount, and other accessories included before purchase. The legality of acquiring and using high-capacity magazines depends on the firearm type, license, and applicable restrictions in Estonia.

Frequently Asked Questions

Is the SIG Sauer M400 FORGE semi-automatic?

Yes. The rifle fires one shot per trigger pull and automatically loads the next round into the chamber. This civilian configuration does not have a fully automatic fire mode.

Can both 5.56 NATO and .223 Rem ammunition be used with this rifle?

The official caliber marking is 5.56 NATO. Use only ammunition permitted by the rifle’s markings and the manufacturer’s manual. While suitable .223 Rem cartridges are often used in rifles with a 5.56 NATO chamber, always check the compatibility of the specific cartridge.

What is the barrel length?

The barrel length is 406 mm or 16 inches. It is a cold-hammer-forged steel barrel.

What is the 1:7" twist rate suitable for?

The fast 1:7" twist rate stabilizes many medium and heavier 5.56 NATO bullets well. Actual accuracy depends on bullet length, weight, ammunition, and the specific rifle.

What trigger is installed on the rifle?

The rifle features a flat-faced TriggerTech Duty two-stage trigger, with a manufacturer-specified pull weight of 3.5 lbs or approximately 1.59 kg.

Is a red dot sight included?

Yes. The set includes a SIG Sauer ROMEO-MSR Gen II with a 2 MOA dot.

Does the rifle have open sights?

The manufacturer’s configuration does not specify separate mechanical sights. Backup sights must be selected and installed separately if needed.

Does the handguard touch the barrel?

No. The handguard is free-floating and does not typically contact the barrel. This reduces the effect of support or accessories attached to the handguard on barrel harmonics.

Can additional accessories be installed on the rifle?

Yes. The handguard features M-LOK slots and a full-length Picatinny rail on top. When installing accessories, ensure compatibility, weight, and that they do not interfere with safe handling of the firearm.

Does the muzzle have threading?

Yes. The muzzle thread is 1/2"-28, and an A2 Birdcage flash hider is factory installed. When choosing another muzzle device, check the thread, caliber compatibility, and legality.

Is a 30-round magazine included?

The manufacturer’s configuration includes one 30-round polymer magazine. The transfer and use of this magazine depend on firearm and magazine restrictions in Estonia and the purchaser’s legal rights.

What are the requirements for purchasing the rifle?

This is a restricted civilian firearm. Purchase and possession require an appropriate acquisition permit or firearms license, and transfer is carried out according to valid firearms law and seller instructions.

When is the SIG Sauer M400 FORGE the right choice?

The SIG Sauer M400 FORGE is suitable for shooters who want a well-equipped factory AR-15 rifle and do not wish to immediately replace the trigger or primary optic after purchase. The TriggerTech two-stage trigger, ROMEO-MSR Gen II red dot sight, and free-floating M-LOK handguard form a practical starter set for training and sport shooting.

The 406 mm barrel and mid-length gas system offer a balance between rifle dimensions, bullet velocity, and operating cycle. The six-position Magpul SL-K stock allows adjustment of length of pull to fit the shooter’s build, clothing, and shooting position.

If the main purpose is precision shooting at longer distances, a magnified optic may be more suitable than a 1× red dot sight. For those seeking a smaller and lighter platform, consider another configuration, but it must comply with firearm regulations in Estonia.

Recommendations

We recommend checking the tightness of the ROMEO-MSR Gen II mount before first use and zeroing the sight with the rifle at a certified shooting range. The 2 MOA dot is suitable for quick target acquisition, but the point of impact depends on the chosen zeroing distance, ammunition, sight height, and the individual behavior of the rifle.

With the TriggerTech two-stage trigger, learn to distinguish the first stage movement and the clear break of the second stage. The trigger mechanism must not be modified or adjusted outside the manufacturer’s instructions. After initial training, check the screws on the handguard, sight, and other attached accessories.

The mid-length direct impingement gas system requires regular cleaning and proper lubrication. After shooting, inspect the bolt carrier, bolt, chamber, and bore. Use only quality ammunition that matches the rifle’s caliber marking, and always follow the manufacturer’s manual.

Factory-equipped AR-15 for training and sport shooting

The SIG Sauer M400 FORGE combines a 406 mm cold-hammer-forged barrel, mid-length gas system, TriggerTech two-stage trigger, free-floating M-LOK handguard, and ROMEO-MSR Gen II red dot sight. The Moss Green Cerakote finish gives the rifle a distinctive appearance and helps protect metal surfaces from environmental effects.

Attention! The modification of the weapon may vary, ask the Jahipauna stores for more information.