SigSauer AR-15 M400 Tread: A Cut Above at a Cut Rate Price

July 31, 2020 Topic: Technology Blog Brand: The Buzz Tags: RiflesGunsSig SauerDefenseAR-15

SigSauer AR-15 M400 Tread: A Cut Above at a Cut Rate Price

With the AR-15 market currently being driven by quality and price, SigSauer has responded with the M400 TREAD.


With the AR-15 market currently being driven by quality and price, SigSauer has responded with the M400 TREAD. A stylish, and incredibly equipped carbine, designed as the best fit out-of-the-box for a wide variety of skill levels and body types. Impressed at first glance, I was ready to hit the course and find out if this rattlesnake inspired carbine can live up to its optimally defensive namesake.



To start on the bench for a 100-yard test, I worked with the ROMEO5 optic. Minimal effort was needed to zero the TREAD and I was impressed from the start with how flat and smooth this carbine performs. Putting the TREAD through a range of competition conditions and field exercises, the crisp trigger was easy to control and I was able to bring my groupings under two inches with regularity. 

For the short-range, and the faster-paced work tested there, the slim design of the handrail really came to play for accuracy on the move. Another design feature of four grooved lines on the magazine well improved my grip ability and together those features made a difference in the overall stability for fast-paced drill work. Less bulk and weight, with the added texture in my grip, allowed me to focus on my trigger pull and my target, (as well as not falling on my face) and the results were consistent. 


The long course and the short-range work were a long day of shooting, and the entire day was free of failure to feed or fire. The short course was a harder environment for this SBR, and inevitably I uncovered the answer to my curiosity about the heat. All of my fingertips survived, but there is some serious heat to that handrail when you get busy. Gloves are a must for anyone intending to do any kind of faster firing work. All in all, with over 1,200 rounds throughout the day of different weights and brands, I was very pleased with the consistency of the TREAD. 


On most of the short-range tests on a ten to twenty-five-yard course, I stuck with the TREAD accessory line, ditched my optic for TREAD Iron Sights, and mostly worked with SigSauer 60G HT factory ammo. Honestly, I cannot say enough how happy this little AR/pistol made me with its lightweight and smooth handling. The Magpul SL-K Stock was comfortable against both shoulder and cheek. With two QD sockets on the lower, sling connections are a breeze with options to add another MLOK point along the upper. The small footprint works well with the lighter weight and sleek design. Providing a consistently flat shoot, with a snappy trigger and easy to manipulate mag release on either side, this weapon makes getting through the quick courses a breeze. The placement, styling, and consistency of the features make this a weapon you’ll feel comfortable handling your first time through a course.


Equipped with a single-stage/hard-coat trigger, this is let’s say… a soft spot on the TREAD’s resume. On the long course, the 6.5 tested weight was a bit of a hindrance in getting the groupings where I wanted them. On the short course, that snappy feel was very easy to work with. Smooth, with a quick reset and little to no grit, this trigger is satisfactory. I’d be likely to recommend an upgrade for the persnickety, but any first-time carbine owners will be quite happy. 

Magazine & Reloading 

Included with the TREAD is one thirty-round mag, and the binary features can be best understood with the reloading drills. My fumbling through working left-handed in drills reinforced my pleasure that SigSauer included the two-sided mag release that is so easy to reach from either side of the grip. Without being too far out of reach, and with the slight adjustment to the depth of the right side lever to avoid interfering with your trigger finger, Sig achieved what they have promised in this being a weapon that can fit anyone, regardless of the size of your hands or which one you write with.

Length and Weight 

Staying on par with its short-barreled AR/Pistol peers, the TREAD has an overall length of 30.8”. With an adjustable stock, adjustments to someone with a smaller frame are simple and effortless. This weapon is made to be used in any situation, and the forged aluminum lower, reinforced with a spring tension plunger to provide a more solid and wiggle-free connection to the upper, allows for a lighter overall weapon that is more comfortable to carry and shoot. Rounding off the dimensions with a 7.5” height mention, the TREAD is sleek and ready to carry. 

Recoil Management 

Comfortable and easy to hold on to, the recoil management is not a significant factor for this carbine. With a free-floating barrel under the ultraslim handrail, it is easy to keep a firm grip on that rigid surface to reduce muzzle flip. Unlike other M4 models, the TREAD has a properly sized gas port on its mid-length barrel and stays flat while shooting.


A direct impingement AR15, with a mid-length gas system and a 16 inch 1:8 Twist barrel, the TREAD is almost entirely a binary weapon with many features not generally found at this price point for the left-handed shooter. Ambidextrous safety and mag release, each designed well to ensure ease of use without getting in the way on either side, are a well thought out set of features. Considering all of the features and the overall quality of the way the TREAD feels in my hands, it is remarkable that the price tag comes in well under $1,000. Yes, you read that right. Not only is this weapon a cut above, but it’s also priced like last year's Honda. Listed MSRP at $951, the SigSauer M400 TREAD can usually be found for purchase at $799. To be perfectly honest, that may be in part due to the hopes that you will load up on the TREAD accessory line to customize your AR, but you really can’t beat this price tag for what you’ll be getting.

My Verdict? 

The TREAD is a winner for almost everyone. It is marketed for the first time buyer for a reason. It’s a great carbine to shoot with little adjustment needed. Being quite well built, and performing accurately and reliably, this weapon is ready to roll. The TREAD line of accessories does offer quite a bit of options to keep your preferred configuration consistent with fit and finish. With all of this on the table, the price tag on this rockstar makes it a slam dunk purchase for any first-time buyer and awfully darn tempting for the experienced shooter who may or may not need to hide those receipts from his wife. If you’re on the fence, I don’t think you can go wrong with this standout TREAD from SigSauer.

Richard Douglas is a firearms expert and educator. His work has appeared in large publications like The Armory Life, Daily Caller, American Shooting Journal, and more. In his free time, he reviews optics on his Scopes Field blog.

Image: Sig Sauer.