SIG SAUER M400 TREAD V2 5.56 NATO 16″ Moss Green
Pros & cons
What works
- Weighs 6.8 lbs unloaded — 0.9 lbs lighter than a comparable Diamondback DB15 with a similar 16-inch stainless barrel.
- Includes SIG Matchlite 2-stage trigger — a $150-200 retail value upgrade over standard mil-spec single-stage units.
- Mid-length gas system reduces felt recoil impulse by approximately 15-20% compared to carbine-length systems with similar ammunition.
- Ambidextrous safety and QD sling points on lower receiver standard — features often missing on rifles under $900.
Trade-offs
- No iron sights included — adds $80-$250 immediate cost for quality BUIS or a primary optic.
- Moss Green Cerakote finish shows wear more visibly than black oxide on the bolt carrier group and high-contact areas after 500+ rounds.
- Free-float handguard has a smooth, non-textured surface — requires M-LOK rail sections or direct-attach accessories for secure grip, adding bulk and cost.
Video review
Expert review
Specs at a glance
About this product
The SIG SAUER M400 TREAD V2 5.56 NATO 16″ Moss Green is a direct-gas-impingement modern sporting rifle engineered as a modular, optics-ready platform for intermediate-range precision shooting and dynamic training. SIG developed the TREAD line as a purpose-built AR platform that strips away marketing fluff to deliver core performance components in a ready-to-accessorize, mid-tier package. It bridges the gap between basic entry-level platforms and full-custom builds for shooters who want proven mechanical reliability without proprietary lock-in.
What is the SIG SAUER M400 TREAD V2 used for?
This rifle is designed for repetitive fire training, intermediate-range target shooting, and as a foundation for a duty or performance-oriented custom build. Its mid-length gas system, stainless-steel barrel, and two-stage match trigger make it mechanically capable of sub-2 MOA groups with match-grade ammunition under proper conditions. The rifle excels during multi-stage drills because of its ambidextrous controls and compatibility with near-universal AR-15 aftermarket parts, allowing quick personalization of ergonomics, sighting systems, and accessory placement without gunsmithing.
How does the SIG SAUER M400 TREAD V2 compare to a Stevens 334 Rifle?
The M400 TREAD V2 is a semi-automatic gas-operated platform with a 30-round detachable magazine, while the Stevens 334 is a bolt-action hunting rifle available in .308 Win. The SIG is clearly superior for rapid follow-up shots and high-volume dynamic training, chambered in the lighter-recoiling 5.56 NATO cartridge. The Stevens 334, however, will generally deliver better mechanical accuracy with a wider range of hunting ammunition and is better suited for applications where single, highly precise shots at longer ranges are required—it’s not a faster choice, but a different-purpose tool.
What does it weigh and what are the dimensions?
The unloaded rifle weighs 6.8 pounds without an optic or magazine installed, and its overall length from muzzle crown to stock end measures 34.75 inches with the stock fully extended. With the Magpul SL-K stock collapsed to its shortest position, the length of pull reduces to approximately 9.5 inches, accommodating shooters with varying arm lengths. The rifle’s center of gravity balances just forward of the magazine well, which helps with muzzle control during rapid fire sessions but adds noticeable front-end weight compared to pencil-profile barreled builds.
Who is this NOT for?
This rifle is not suitable for jurisdictions with magazine capacity restrictions below 30 rounds or assault weapons bans covering AR-platform features like threaded barrels. It’s also a poor first rifle choice for budget-minded shooters looking for a ready-to-hunt package under $800, as optics, sling, light, and additional magazines likely add $400-$700 to the total system cost. If you specifically need a platform for converting into a short-barreled rifle under 16 inches, starting with a complete pistol variant is a smarter buy to avoid NFA paperwork and a permanent tax stamp on this 16-inch barrel.
What's in the box?
You receive the complete rifle, one steel 30-round detachable magazine, a SIG owner's manual, a chamber safety flag, and a SIG-branded hard case with cut-out foam. The case measures 42 inches internally, providing ample room for the rifle with a red dot sight mounted but will be too short for most scoped configurations without removing the optic. Notably absent are iron sights, a sling, or any cleaning kit components—common exclusions in this product tier that add roughly $150-$300 to your initial accessory budget.
Is the SIG SAUER M400 TREAD V2 worth it at $1119.99?
Yes, at $1119.99, this rifle represents strong value for shooters who want a duty-grade intermediate AR platform without the $1,700-$2,200 price of a fully-kitted Daniel Defense or Colt counterpart. You’re paying a couple hundred dollars more than a base PSA or Anderson for a significantly better two-stage trigger, a corrosion-resistant stainless-steel barrel, and fully ambidextrous controls—components that would cost over $400 to upgrade independently. The main justification for spending less would be if you intend to immediately replace the handguard, gas block, or bolt carrier group with premium parts, making the included upgrades redundant.
Key attributes
| upc | 798681688012 |
| manufacturer | SIG SAUER |
| manufacturer part number | RM40016BTRDV2G |
| action | Semi-Auto |
| atf type | MODERN SPORTING RIFLE |
| barrel length | 16" |
| caliber/gauge | .223 REM/5.56 NATO |
| capacity | 30 + 1 |
| color | GREEN |
| length | 34.4500 |
| product type | AR |
| safety | Ambidextrous |
| shipping weight | 8.5 |
| sights | No |
| state restriction (ca) | NO DIRECT SHIP TO CALIFORNIA |
| state restriction (ri) | NO DIRECT SHIP TO RHODE ISLAND |
| state restriction (wa) | NO DIRECT SHIP TO WASHINGTON |
| magazine included | 1 x 30-Round |
| model | M400 |
| number of magazines | 1 30 rd. |
| package height | 2.8 |
| package width | 9.0 |
Frequently asked questions
- Is it compatible with standard AR-15 parts?
- Yes, the M400 TREAD V2 uses a mil-spec AR-15 lower receiver and bolt carrier group dimensions, making it compatible with the vast majority of aftermarket triggers, grips, and stocks. The upper receiver and handguard rail height are also mil-spec, ensuring proper alignment for optics and IR laser devices. The only semi-proprietary element is the M-LOK enhanced handguard mounting system, which still accepts standard barrel nuts and gas tubes.
- Does it fit in a standard 36-inch rifle case?
- No, with a total length of 34.75 inches and the Magpul SL-K stock fully extended, this rifle requires a case with an internal length of at least 37 inches for safe clearance. I recommend a SKB 42-inch hard case or similar for transport, allowing enough room at the muzzle for a flash hider or muzzle brake. Most sub-36 inch cases are designed for rifles with folding stocks or shorter barrels.
- How long does shipping take to an FFL?
- Ironclad Armory processes and ships complete rifles within 2-3 business days after FFL verification, with transit time averaging 3-5 additional business days via ground carrier. You must provide your chosen FFL's contact information and license before the order ships—delays typically occur during the verification step, not the shipping itself. We ship via FedEx with adult signature required at delivery.
- Does this work with a .223 Wylde chambered barrel?
- The rifle ships with a standard 5.56 NATO chamber, which safely fires both 5.56 NATO and .223 Remington ammunition; a .223 Wylde chamber is a different specification. You cannot simply swap the barrel for a .223 Wylde without fitting and headspacing the new barrel extension to your specific bolt—this is a gunsmithing task requiring specialized tools and gauges. For most shooters, the factory 5.56 NATO chamber provides optimal compatibility and safety margin for both cartridge types.