Last tested: October 2026

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On this page: Verdict · Our Verified Review · The Good · The Not Good · Product Description · What others think · FAQ

The verdict Good: A great entry rifle by a very reliable company, with no functional issues in six years.

Our Verified Review

Owned and tested by our reviewer, Elmir

Elmir has had his SIG Sauer M400 TREAD for six years. His has the 16-inch barrel, and he runs it with a SIG Sauer 1×6 optic. He uses it for tactical fitness competitions.

In his words, it’s a great entry rifle by a very reliable company, and a very reliable rifle. He has had no functional issues with it, and it has been super reliable with both 5.56 and .223. He installed a PSA (Palmetto State Armory) flat trigger.

The one thing he points out: the handguard does get hot fast, because it is a low profile handguard. Otherwise, it has held up through everything he has put it through. His verdict: Good.

The Good ✅

• Very Reliable: Super reliable, with no functional issues in six years.
• Eats 5.56 and .223: Reliable with both 5.56 and .223.
• Great Entry Rifle: A great entry rifle by a very reliable company.
• Holds Up: It has held up through everything he has put it through.

The Not Good ❌

Flaws, but not deal-breakers.

• Handguard Gets Hot Fast: The low profile handguard does get hot fast.

Product Description

Specs and maker’s details

The SIG Sauer M400 TREAD is SIG’s AR-15 rifle chambered in 5.56 NATO. SIG lists a 16-inch stainless steel barrel, a free-floating M-LOK handguard, a single-stage trigger, ambidextrous controls, a Magpul SL-K 6-position telescoping stock and a mid-length gas system, at 30.8 inches long and 7 lb. SIG now lists the original TREAD as discontinued and sells the M400-TREAD V2.

Elmir’s has the 16-inch barrel, and he runs it with a SIG Sauer 1×6 optic.

What others think

How our verdict compares with other reviews

Overall reception: Well regarded as a solid budget AR. We found no reliable rating figure for Elmir’s version, but reviewers at Gunmade and Shooting Illustrated rate it as accurate and dependable for the price.

Where owners agree: Reviewers and owners call it reliable, with handy ambidextrous controls. They also agree the factory handguard gets very hot under rapid fire, and that the stock trigger is heavy: Shooting Illustrated measured 7 pounds, 10 ounces.

Where owners disagree: Whether to upgrade it or buy up. Many owners swap the trigger and handguard, though the proprietary barrel nut makes handguard swaps harder, while others on Reddit say to buy a later Tread model that comes with a two-stage trigger and better handguard.

Our take: Elmir matches the consensus. Six years with no functional issues on 5.56 and .223, a handguard that gets hot fast, and he swapped in a flat trigger, like many owners.

Sources (checked Oct 18, 2026): Gunmade review · Shooting Illustrated review · r/SigSauer thread

Frequently Asked Questions

Quick answers to common questions

Is the SIG Sauer M400 TREAD good?

Elmir says Good. He calls it a great entry rifle by a very reliable company, and he has had no functional issues with it.

Is the M400 TREAD reliable?

Super reliable, Elmir says, shooting 5.56 and .223. He has had it for six years with no functional issues.

Does the M400 TREAD handguard get hot?

Yes. Elmir says the handguard does get hot fast because it is a low profile handguard.

What setup does Elmir run on his M400 TREAD?

The 16-inch barrel with a SIG Sauer 1×6 optic, and he installed a PSA (Palmetto State Armory) flat trigger.

Is the M400 TREAD good for competitions?

Elmir uses his for tactical fitness competitions, and it has held up through everything he has put it through.

A huge thank you to Elmir for taking the time to share his honest opinion and for supporting our project. Real reviews from real people are what GoodNotGood is all about, and support like yours is what takes us from good to great. We truly appreciate you!

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