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.
Check out: Sig M400 Upgrade Guide
Our Top Sig Sauer M400 Tread Picks:
Disclosure: All products have affiliate links for earning commission to support the website when you purchase
Holosun 510C - Best Overall
Why use this optic
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.
Large Field Of View – Unobstructed field of view helps shooting with both eyes open and while on the move (slow)
Extended battery life – Solar Failsafe system keeps the reticle alive even if the 50k hours battery life runs out (almost like a fiber optic under light)
2 MOA Dot + 65 MOA Ring - Use 2 MOA dot for precise long distance aiming, and use the 65 MOA to range target & for fast CQB acquisition
Unlimited Eyebox - Aim around barricade, under the car and tight corners without the scope shadow getting in the way
Sig Sauer ROMEO5 - Best Budget Aimpoint Alike Optic
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
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.
Always Ready To Go! The glass etched reticle is always there without battery power during daylight use.
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
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
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
EOTECH EXPS3 - Pros' Pick
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.
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 Durability
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
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
Vortex Micro 3X Magnifier - Extend Your Range
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.
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
As the content creator of badassoptic.com, My background in the firearms industry and shooting sports gives me the experience to recommend tried and true products and keep away subpar ones.