Sig Sauer M400 Tread V2 5.56 NATO
Model: RM400-16B-TRD-V2
Sig Sauer M400 Tread V2 5.56 NATO
Model: RM400-16B-TRD-V2
Full Specifications
About This Firearm
Sig Sauer's M400 Tread V2 pairs a stainless steel 16-inch barrel with the SIG Matchlite Duo two-stage trigger and ambidextrous safety selector — two features that separate it from most mid-tier ARs. The 7075-T6 aluminum upper and lower receivers wear a black anodized finish, and the rifle ships with a Magpul SL-K stock and SIG's own reduced-angle grip. At 104 oz and 35.8 inches overall, it sits right in the middle of the pack for both weight and length among 16-inch ARs.
The Tread V2's two-stage trigger is the headline feature. Most rifles at this tier ship with single-stage mil-spec triggers, while the Matchlite Duo provides a distinct take-up stage followed by a clean wall and break. Competitive shooters and precision-minded owners consistently point to this trigger as the reason to pick the Tread over similarly equipped alternatives. The SIG 3-prong flash hider is effective, and the 6-position collapsible stock fits a wide range of body types.
Buy the Tread V2 if a factory two-stage trigger and ambidextrous controls matter to you more than included iron sights. Skip it if you want a rifle with sights in the box or if you prefer a cold hammer-forged barrel over stainless steel.
Best For
Strengths & Limitations
- The SIG Matchlite Duo two-stage trigger is the standout feature in this tier — no other rifle in this price range ships with a factory two-stage trigger that offers a distinct take-up and clean break.
- The ambidextrous safety selector works for both left- and right-handed shooters without any modification, an advantage the Springfield SAINTs and IWI Zion-15 lack from the factory.
- At 104 oz, the Tread V2 balances light weight with the stainless steel barrel's corrosion resistance, making it low-maintenance in humid or coastal climates.
- Ships with no iron sights at all, which means an optic purchase is mandatory before the first range trip — unlike the Springfield SAINT and SAINT Victor, which include usable sights.
- The stainless steel barrel, while corrosion-resistant, is generally considered less durable over extreme round counts than a chrome-lined or nitride-treated chrome moly barrel used by most competitors in this group.
Category Rankings
How the Sig Sauer M400 Tread V2 5.56 NATO ranks among full-size 5.56 NATO rifles.
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Frequently Asked Questions
How does the SIG Matchlite Duo trigger compare to a mil-spec trigger?
A standard mil-spec trigger is a single-stage design with a gritty pull that breaks somewhere between 6 and 8 lbs. The Matchlite Duo is a two-stage trigger with a lighter, smoother take-up stage followed by a clean break at the wall. The two-stage design lets the shooter prep the trigger during aiming and then break the shot with minimal disturbance. It is a meaningful accuracy improvement for both range shooting and precision work at distance.
Is the stainless steel barrel on the Tread V2 as durable as a chrome moly barrel?
Stainless steel barrels offer excellent corrosion resistance and tend to shoot very accurately, but they are generally considered to wear faster at high round counts compared to chrome-lined or nitride-treated chrome moly barrels. For most recreational and training shooters who put a few thousand rounds per year through their rifle, the stainless barrel will last many years. High-volume shooters running 10,000+ rounds annually may see throat erosion sooner than with a CMV barrel.