9 Best Sig Sauer M400 Tread Upgrades [Entry Level To PRO]

We've put together of list of the 9 Best Sig Sauer M400 Tread Upgrades to significantly improve the rifle's performance even more.

Let's take a look

Disclosure: All products have affiliate links for earning commission to support the website when you purchase

Sig M400 TREAD

The M400 Tread may appear to be an entry level AR for the Sig Sauer company, but it's definitely not an entry level like others where a complete top to bottom face lift is required!

Other generic ARs have to spend extra money to get

  • Ambi safety selector - Better left / right control ergonomics
  • Ambi mag release - Works for left / right handed shooters
  • Magpul SLK stock - Rock solid, no wobble, slim profile
  • Reinforced Built-In QD Slots - Added sling attachment point 

Improves Handling & Control

Troy Enhanced Trigger Guard - Works Better With Gloves

Troy Enhanced Trigger Guard SGUA-AMB-00BT-00

The existing M400 Tread trigger guard has a bow profile to it, but it's still not big enough for glove users.

If you wear gloves in the winter when shooting, you need a bigger trigger guard to clear the gloves.

geissele mk16 handguard

Right out of the box, the Sig M400 Tread comes with a M LOK rail, but it doesn't seem to dissipate heat well after rapid firing.

So when it's time to upgrade the handguard, check out the Geissele MK16 rail.

Available for 9.3", 10.5", 13.5". A2 front sight must be removed first and low profile gas block is required for installation.

Better Heat Resistant - Full rail slot cuts reduces weight and maximize heat dissipation

Laser Device - Mount laser devices with much more accuracy

M LOK Compatible - Mount any MLOK accessories like lights, laser, and grips you want at the 2, 3, 5, 6, 8, 9, 10, and 12 O'clock positions.

Rock Solid Receiver Lock - Anti rotational tab holds on to the M400 standard A2 upper receiver from the left and right to prevent any shifting

geissele rail anti rotational tabs

Thick Barrel Nut - Long cantilever beam barrel nut design holds the handguard tight and sturdy along the bore, and doesn't flex or wobble

Raptor Charging Handle - Increased Durability & Ergonomics

Radian Weapons Raptor Ambidextrous Charging Handle for AR15/M16, Tungsten Grey, R0002

The raptor charging handle should be added to any AR during the upgrade process.

Ambi -  Charge the bolt from the right side during shoulder transition

Increased Durability - Charge it hard without shearing the handle over time unlike the one out of the box 

Much Larger Latch - Easier to grip & pull with a serrated surface

See More: Best AR15 Charging Handles 

Compare Deals:


Recoil Reduction

Surefire MB566 Muzzle Brake - Mitigates Recoil


This thing can turn any budget AR15 builds into a low recoil pulse rifle that competition shooters love to shoot fast and accurately. 

Reducing muzzle flip significantly to get follow up shots on target FAST! This muzzle brake minimizes side blast and rearward concussion effects for the shooter.

Compatible With Surefire Suppressor with multiple bearing surfaces for superior suppressor can alignment.

Compare Deals:


BCM Gunfighter Grip - Better Handguard Grip

bcm vertical foregrip

Buy the MLOK version and slap it right on Sig M400 Modular MLOK handguard.

Enhanced Grip Ergonomics - Drive the muzzle faster to the target with an rock solid grip on the rifle and to operate a weapon light at the same time.

Reduce Sway -  C clamp grip ergonomics helps reduce sway by providing better grip leverage

Way Better Recoil Control - Reduce horizontal and vertical muzzle recoil shifts for faster follow up shots (Helps even more if using a muzzle brake)

Check out more Grips Here

Compare Deals:


KNS Anti Walk Pins Gen 2 - Solid Trigger Group Retention

KNS Precision AR15/M16 Gen 2 MOD 2 Non-Rotate Trigger/Hammer Pins .154 Diameter-Stainless Steel, NRTHPMOD2-154-SS

Use this anti hammer and trigger rotation pin to lock down the trigger system to prevent trigger malfunction. No modification to gun required!

Use .154 Diameter for Sig M400 Tread lower receiver

Quick Installation - New threaded pins to replace factory pins. Just lock them in place and you're done!

Rock Solid Performance - Shoot as much as you like without worrying pins falling out in the field. 

No Wear To Receiver - Special anti-creep retainers prevent wear on your lower AR-15 receiver

Timney Single Stage Trigger - Smooth Trigger Pull


M400's single stage trigger works but the Timney AR15 single stage 3lb trigge is better as far as trigger pull and reset experience go.

Quick Installation - Install two trigger pins and you are done!, no gunsmithing or re-fitting required.

Fast Trigger Reset - Crisp trigger break, almost no pre-travel, and the short trigger reset puts the trigger back in position for follow up shot immediately

Reduced Trigger Pull Weight - Reducec trigger pull weight down to just 3 lbs for a much tighter shot group at longer ranges with slow trigger squeeze.

Check out more AR15 Drop In Triggers Here

Compare Deals:


Geissele Super 42 Braided Buffer Spring - Improved Spring Service Life


Eliminated Spring Twang Sound - The braided wire spring kills the annoying twang sound and preserves spring harmonics inside the buffer tube.

We recommend the Geissele Super 42 Braided Spring with H1 or H2 buffer for 16" standard gas system

Increased Cycle Life - The spring operates ONLY at around ~35% of its maximum stress load to increase its service life.

Improved Spring Haromincs - The spring flexes separately from each other like a harmonic damper to displace excess energy to prevent failure.

Improved Reliability - The Braided wire increases bolt return force to ensure proper round chambering when dealing with a dirt or steel case ammo

Compare Deals:



EOTech EXPS3 - Best Holosight

eotech exps3 pov 1

Any budget and high end optics will work on the Sig M400, but the EOTech EXPS3 just felt right with that large field of view.

This is an top brand holographic sight that just goes perfectly with a top brand AR.

Point & Shoot – Aim with both eyes open to maximize situational awareness & parallax free reticle gives flexible head movement behind the optic

Rock Solid Mount – Mount it on the Sig M400 as well as any other rifles you have

EOTECH exps3 reticle outdoor

Smaller optics also work, please check out our red dot sight guide for more information.

3+ Stores

Also check out our complete best AR15 guide here