Here are the 7 best scopes for Sig Sauer M400 Tread.

Let's put a great optic on this out-of-the-box already customized budget AR15 and have some fun with it or put it on your other rifles.

Best Sights For Sig M400 Tread

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  • Best Overall
  • Affordable Aimpoint Micro Clone
  • Best For Astigmatism
  • Best Holographic Sight
  • Best For The Money
  • Best Budget LPVO
  • Best 3X Red Dot Magnifier

Holosun 510C - Best Overall

holosun 510c pov reticle

The Holosun 510C is the best durable entry level reflex optic up to date for your Sig M400 TREAD before moving onto something much more expensive.

First off, the large field of view is a standout feature. It made shooting with both eyes open a breeze, especially when I was moving, albeit slowly. I felt more aware of my surroundings and less restricted in my vision.

holosun 510c front lens

The Solar Failsafe provides backup power if the battery dies. So far it has not, and the solar panel has never been used. 

holosun 510c reticle selection

Cycle through them by pressing "-" for 3 secs

The 2 MOA Dot and 65 MOA Ring combination is another plus. I used the 2 MOA dot for precise, long-distance aiming. It was pinpoint accurate.

The 65 MOA ring helped me quickly acquire targets in close-quarter battles and even assisted in ranging target distances.

Sig Sauer ROMEO5 - Best Budget Aimpoint Alike Optic

sig sauer romeo5 iso view
Why we picked this for the new gun owners - The Sig Sauer ROMEO5 is a much better Aimpoint Micro alike optic than other clone optics. It works with all aftermarket Aimpoint Micro mounts.

Motion Activated - MOTAC powers up the optic and shuts down when sitting idle to save battery and last as long as up to 40K hours

Sig For Sig - If you want a Sig Sauer product to match your Sig M400 Tread, this is a great budget option sight to buy
romeo5 pov red dot reticle on steel target

Easy To Pick Up Reticle - The same 2 MOA size dot other high end optics use for medium & CQB range shooting

Why Use A Prism Scope? This is by far the best for shooters with astigmatism, and for a truck rifle setup without worry about the battery life or the reticle disappearing at all. 

Works For Astigmatism - See the reticle clearly almost like wearing a pair of corrected lens. No blurry reticle or image for precise aiming after adjusting eye piece

vortex spitfire ar indoor eyebox range

Better Reticle Centering -  Eye box constraint forces consistent cheek position for precise long distance aiming on 1X than a red dot by reducing parallax offset

Works For Crossed Eye Dominance - Use tall mount to tilt the gun to aim for crossed eye dominant shooters

windage adjustment vortex spitfire ar 1x prism sight

Illuminated DRT Reticle - See reticle in low light conditions and much sharper image than another fixed 1X optics on the market

Built In Eyepiece - Adjust diopter image clarity to the shooter's particular eye sight 

5.56 BDC - Shoot up to 700 yards with a separately (yard) labeled turret knob

Read Detailed Spitfire AR Review Here

EOTECH EXPS3 - Best For Passive Aiming

eotech exps3 aiming steel target

Why Upgrade To EOTECH EXPS3? - This is an operator grade sight for all serious shooters period, and it just looks sexy on the Sig M400 TREAD

It's the same optic real world military and law enforcement professionals use to deal with real life situations, and you can use it for training and personal defense.

Eotech exps 3 tan on mk18

Shoot With Both Eyes Open - Just like the Holosun 510C, but this one is enclosed body design meaning the holographic reticle emitter is fully protected from dirt and moisture

CQB Holdover - Use the bottom of the 68 MOA ring for fast close range holdover to compensate CQB sight over bore offset.

Fast Mount & Demount - Just swing the lever shut on the rail to lock the optic in place. Adjust the side screw with positive clicks to tighten the lever if it's loose

Raised Height - The integrated QD also gives the shooter 1/3rd co-witness height on the Sig M400 for a comfortable cheek height position. Also lines up with most magnifier scopes 

NV Compatible - NV mode reticle is only visible for night vision goggle if you train with these high end ninja gears

Aimpoint Patrol - Best For The Money

Why Use The Aimpoint Patrol - The Aimpoint Comp series optics is by far the best durability carbine red dot sights on the market under $480. 

If the SIG M400 TREAD is your first AR, and you want a top brand optic, the Aimpoint Patrol is the way to go.

Precise Aiming Reticle - 2 MOA dot just like other combat grade optics

Always Ready & Always On - Lasts over 3 years on just one single 3V type 2L76 or DL1/3N battery. Just pick it up and aim!

Even Survives Fire - The hard anodized aerospace grade aluminum alloy housing protects the optic internals from hash combat environment and fire to keep the fight on!

Included QRP2 Mount - No extra money spent on buying mounts, It comes with a mount for budget buyers!

See Through Flip Covers - Aim through the lens covers even if it's in the closed position during an emergency. It also keep the glass clean.

If I had to choose between using an Aimpoint Micro or The Aimpoint Comp for a compact setup, I would choose the Aimpoint Patrol Optic for just under $480.

Vortex Viper PST Gen 2 1-6X - Best Mid Range Scope

vortex 1-6x24 TMCQ pov

Why Pick The Vortex Viper PST Gen 2 1-6X24 - Combining mid range and CQB capability into one package! This is by far the best low power variable scope for an AR15 for $800. 

Fast 1-6X Transitions - Dialing between close range targets and mid range targets fast within half a second. Its an two-in-one aiming solution for any rifle applications.

Crystal Clear Sight Picture - Vortex glass gives excellent edge-to-edge image detailing for a minimum of glare distraction.

Ultra Tough Glass - Vortex uses ArmorTek ultra hard lens coating provides the last line of unbreakable defense against scratches and other harsh elements

Better Low Light Transmission - More light translates into a vivid view of the target, even at long-range. Proprietary Viper lens coatings are ideal for hunting in dense wood and underbrush.

The Vortex Razor HD GEN 3 1-10X is also a great option if you're ready to drop $2000

Browse more LPVOs here

Vortex Micro 3X Magnifier - Extend Your Range

eotech exps3 and vortex micro 3x to view

Why Use A Magnifier - Extend your 1X power red dot to 3X in no Time. It's a great add on feature to a red dot for non LPVO users.

Tuck It Away When Not In Use - PowerCam pivot mount swings the optic to the side and locks it in place when done using.

eotech exps 3 vortex micro 3x flipped

Reversable Orientation -  Change the pivot mount orientation at any time for right or left-handed use.

Even Smaller Than Before - Same magnification capability as previous generation magnifiers, but smaller & has better eye relief distance & 28% more field of view

65 moa ring reticle


  • Magnification 3x
  • Objective Lens Diameter 22 mm
  • Eye Relief 2.64 inches
  • Linear Field of View 38.2 feet @ 100 yds
  • Angular Field of View 7.28 degrees
  • Length 2.9 inches
  • Weight 9.55 oz