# SIGM400 Tread: 5.56 NATO, 16" Semi-Auto Rifle - Black

**Brand:** SIG Sauer
**Category:** AR Style Rifles
**Caliber:** 5.56 NATO

## Specifications

- **Caliber:** 5.56 NATO
- **Barrel Length:** 16"
- **Capacity:** 10 rounds
- **Overall Length:** 30.8"
- **UPC:** 798681632954
- **SKU:** UCE3nOjlq

## Description

The SIGM400 is a direct-impingement semi-automatic rifle chambered in 5.56 NATO/.223 Remington. It has a 16-inch barrel, weighs 7 lbs, and ships in black. The 1:8 twist rate stabilizes a wide range of bullet weights, which gives it flexibility across different load types.

### Key Specifications
- **Model:** SIGM400
- **Caliber:** 5.56 NATO - .223 Remington
- **Action:** Semi-Automatic
- **Capacity:** 10 rounds
- **Barrel Length:** 16 inches (406 mm)
- **Overall Length:** 30.8 inches (782 mm)
- **Height:** 7.5 inches (191 mm)
- **Width:** 2.5 inches (64 mm)
- **Weight:** 7 lbs (3.2 kg)
- **Twist Rate:** 1:8
- **Operating System:** Direct Impingement

### Detailed Features

The direct-impingement operating system is mechanically simple, which keeps parts count low and maintenance straightforward. The 16-inch barrel hits the legal minimum for a non-SBR configuration while keeping overall length at a manageable 30.8 inches. At 7 lbs, it's neither ultralight nor heavy for the AR-15 platform.

The 1:8 twist handles bullets in the 55-77 grain range reliably, so users aren't locked into a single load weight. The black finish resists corrosion and wear under typical use conditions.

### Usage Scenarios

The SIGM400 fits common AR-15 use cases: home defense, range shooting, and light hunting. The 5.56 NATO chambering also accepts .223 Remington, which is widely available and generally less expensive. The 10-round capacity is below what the platform can accept. Standard AR-15 30-round magazines are compatible depending on local regulations.

## What Customers Say

*AI-generated insights from customer reviews*

The SIGM400 Tread gets generally favorable reviews in the AR-15 community, with accuracy and build quality as the main selling points.

Owners frequently mention that accuracy out of the box is good, with effective performance at typical rifle distances. The 1:8 twist rate flexibility and the SIG name carry weight with buyers who prioritize reliability from the factory.

Versatility is a recurring theme. Users note the platform adapts well to optics and accessories, and the standard AR-15 form factor means the aftermarket parts selection is broad. For buyers who plan to customize, the SIGM400 gives a solid base.

On the critical side, weight comes up regularly. At 7 lbs, some owners find it heavier than comparable AR-15 options from other manufacturers, which affects handling in extended carry or competition use. The 10-round factory capacity limitation also draws comment, while magazine compatibility with standard AR-15 magazines exists, shipping with a 10-round magazine is a noticeable limitation on the base configuration.

The price-to-feature ratio is discussed positively overall, with most owners considering it competitive for a SIG-branded rifle. Some mention specific components (trigger, handguard) as areas where the Tread configuration leaves room for upgrades compared to higher-end AR-15 builds.

## Pricing

**1 offers available**

| Vendor | Price |
|--------|-------|
| Guns Com | $1050.99 |

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*Data from [GunsNation](https://gunsnation.com)*