Sig Sauer M400 for sale
Updated · 49 products · 32 in stock · prices refreshed daily
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SIG SAUER M400 Rose 5.56mm 16in 30rd Rose/Black Semi-Auto Rifle w/ Romeo 5X2 (RM400-16B-ROSE-R5X2)
Brand:
Sig Sauer
Action:
Semi-Auto
Barrel Length:
16"
Caliber:
5.56×45mm NATO
Capacity:
30
Finish Per Color:
Black
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SIG RM400-SDI-16B-P M400 XSERIES 16" 5.56 SDI
Brand:
Sig Sauer
Action:
Semi-Auto
Barrel Length:
16"
Caliber:
.223 Rem/5.56×45mm NATO
Capacity:
30
Finish Per Color:
Black
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SIG SAUER M400-Sentry 5.56mm NATO 16in 30rd Semi-Auto Rifle w/ Romeo5 Gen II & Foxtrot-MSR Full Size Light (RM400-SDI-16B-R5FX)
Brand:
Sig Sauer
Action:
Semi-Auto
Barrel Length:
16"
Caliber:
5.56×45mm NATO
Capacity:
30
Finish Per Color:
Black
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Sig M400 Switchblade 5.56/.223, 11.5" Barrel, Blade Brace, Titanium Elite, 30rd
Brand:
Sig Sauer
Action:
Semi-Auto
Barrel Length:
11.5"
Caliber:
5.56×45mm NATO
Capacity:
30
Finish Per Color:
Grey
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M400 SDI 5.56MM 16" MOSS GREEN RIFLE
Brand:
Sig Sauer
Action:
Semi-Auto
Barrel Length:
16"
Caliber:
5.56×45mm NATO
Capacity:
30
Finish Per Color:
Green
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SIG SAUER M400 SDI 5.56MM 16" FDE 30+1 RIFLE
Brand:
Sig Sauer
Action:
Semi-Auto
Barrel Length:
16"
Caliber:
5.56×45mm NATO
Capacity:
30
Finish Per Color:
Flat Dark Earth
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Sig Sauer M400 Forge 5.56 Nato Rifle 16"Bbl CHF w/ Romeo-MSR Gen II Telescoping Stock Two-Stage Trigger MLOK Hg 1x30Rd Mag RM400-556N-16B-FORGE-CON
Brand:
Sig Sauer
Action:
Semi-Auto
Barrel Length:
16"
Caliber:
5.56×45mm NATO
Capacity:
30
Finish Per Color:
Cerakote
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SIG RM40016BROSER5X210 M400 556 16 OR 10R RS
Brand:
Sig Sauer
Action:
Semi-Auto
Barrel Length:
16"
Caliber:
5.56×45mm NATO
Capacity:
10
Finish Per Color:
Black
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Sig Sauer RM400556N16BFORGEMSGRN M400 Forge 5.56 NATO 30+1 16" Moss Green Cerakote Alloy Receiver w/Picatinny Rail, M-LOK Handguard, Magpul SL-K Black Polymer Stock, Black Polymer Grip, Sig ROMEO MSR
Brand:
Sig Sauer
Action:
Semi-Auto
Barrel Length:
16"
Caliber:
5.56×45mm NATO
Capacity:
30
Finish Per Color:
Green
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Sig Sauer RM400556N16BFORGE10 M400 Forge 5.56 NATO 10+1 16" Black Anodized Alloy Receiver w/Picatinny Rail, M-LOK Handguard, Magpul SL-K Black Polymer Stock, Black Polymer Grip, Sig ROMEO MSR Gen II R
Brand:
Sig Sauer
Action:
Semi-Auto
Barrel Length:
16"
Caliber:
5.56×45mm NATO
Capacity:
10
Finish Per Color:
Black
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SIG SAUER M400 Forge
Brand:
Sig Sauer
Action:
Semi-Auto
Barrel Length:
16"
Caliber:
5.56×45mm NATO
Capacity:
30
Finish Per Color:
Black
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SIG SAUER M400-Tread 5.56 NATO 16in 10rd Semi-Auto Rifle (RM400-16B-TRD-V2-10)
Brand:
Sig Sauer
Action:
Semi-Auto
Barrel Length:
16"
Caliber:
5.56×45mm NATO
Capacity:
10
Finish Per Color:
Black
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SIG SAUER M400 Forge 5.56mm NATO 16in 10rd Semi-Auto Rifle, CA Compliant (RM400-556N-16B-FORGE-CA)
Brand:
Sig Sauer
Action:
Semi-Auto
Barrel Length:
16"
Caliber:
5.56×45mm NATO
Capacity:
10
Finish Per Color:
Black
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M400 Tread 2.0 5.56x45 NATO 16" BBL (1)30RD Mag Black - M400 Tread 2.0 5.56x45 NATO 16" BBL (1)30RD Mag Black
Brand:
Sig Sauer
Action:
Semi-Auto
Barrel Length:
16"
Caliber:
5.56×45mm NATO
Capacity:
30
Finish Per Color:
Black
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SIG SAUER M400 TREAD
Brand:
Sig Sauer
Action:
Semi-Auto
Barrel Length:
16"
Caliber:
.223 Rem/5.56×45mm NATO
Capacity:
30
Finish Per Color:
Green
(0)
Sig Sauer M400 Forge 5.56 Nato Pistol 11.5"Bbl CHF w/ Romeo-MSR Gen II Bsl Brace Two Stage Trigger MLOK Hg 1x30Rd Mag PM400-556N-11B-FORGE
Brand:
Sig Sauer
Action:
Semi-Auto
Barrel Length:
11.5"
Caliber:
5.56×45mm NATO
Capacity:
30
Finish Per Color:
Black
(0)
Sig Sauer RM400556N16BFORGEFDE M400 Forge 5.56 NATO 30+1 16" Flat Dark Earth Cerakote Alloy Receiver w/Picatinny Rail, M-LOK Handguard, Magpul SL-K Black Polymer Stock, Black Polymer Grip, Sig ROMEO M
Brand:
Sig Sauer
Action:
Semi-Auto
Barrel Length:
16"
Caliber:
5.56×45mm NATO
Capacity:
30
Finish Per Color:
Flat Dark Earth
(0)
SIG SAUER M400 TREAD PREDATOR 5.56 NATO 16" BARREL 5RD JUNGLE GREEN
Brand:
Sig Sauer
Action:
Semi-Auto
Barrel Length:
16"
Caliber:
5.56×45mm NATO
Capacity:
5
Finish Per Color:
Green
(0)
Sig Sauer M400 Tread V2 5.56 / .223 Rem 11.5" Barrel 30-Rounds
Action:
Semi-Auto
Barrel Length:
11.5"
Caliber:
.223 Rem/5.56×45mm NATO
Capacity:
30
Finish Per Color:
Black
(0)
SIG Sauer M400 SDI 5.56 AR Pistol - 11.5" - Flat Dark Earth - 1x 30rd Mag
Brand:
Sig Sauer
Action:
Semi-Auto
Barrel Length:
11.5"
Caliber:
5.56×45mm NATO
Capacity:
30
Finish Per Color:
Flat Dark Earth
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Sig Sauer M400 DH3 SDI Competition .223 Wylde 16" 1:8" Bbl Optics Ready Semi-Auto 30rd Rifle RM400-SDI-16B-DH3
Brand:
Sig Sauer
Action:
Semi-Auto
Barrel Length:
16"
Caliber:
.223 Wylde
Capacity:
30
Finish Per Color:
Grey
(0)
SIG M400 PRO LE UPC: 798681654857
Brand:
Sig Sauer
Action:
Semi-Auto
Barrel Length:
16"
Caliber:
5.56×45mm NATO
Capacity:
30
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SIG SAUER M400-TREAD V2 5.56 NATO 16in 30rd Elite Concrete Semi-Auto Rifle (RM400-16B-TRD-V2CON)
Brand:
Sig Sauer
Action:
Semi-Auto
Barrel Length:
16"
Caliber:
5.56×45mm NATO
Capacity:
30
Rounds:
30
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SIG SAUER M400 Tread V2 TacPac 5.56mm 16in 30rd Black Rifle w/ Romeo MSR (RM400-16B-TRD-V2-TACPAC)
Brand:
Sig Sauer
Action:
Semi-Auto
Barrel Length:
16"
Caliber:
5.56×45mm NATO
Capacity:
30
Finish Per Color:
Blued
Marketplace Insights
★ 4.8/5
based on 96 customer reviews across 49 products from 29 retailers
Highly-rated SIG rifle offering excellent accuracy, reliability and value with strong build quality, though occasional QC and shipping description mismatches reported.
What customers like
Accuracy & Performance45%
It's super accurate and the kick isn't too bad at all.
Great Value for Price38%
For the price, I think you'd be hard-pressed to beat it.
Quality & Build32%
Well built and reliable while it's nothing fancy it also nothing missing
Trigger Quality28%
The trigger is nice n crispy.
Reliable & No Malfunctions25%
No problems with jamming. As well as shoots very tight groups.
Common concerns
Incorrect Product Description4%
Standard CTR Stock included not SL-K, no rails nor mlok panels included
Stiff Action/Break-in Issues3%
The guns break open action is entirely too stiff.
Hand Guard Limitations3%
Cannot add QD mount close to upper and lower receiver.
Frequently Asked Questions
Sig Sauer M400 for sale
Is the SIGM400 a 556 or 223?
The SIG M400 is chambered in 5.56 NATO, which also safely accepts .223 Remington ammunition. A 5.56 NATO chamber has slightly more freebore than a .223 chamber, so while both rounds work, you should not fire 5.56 NATO in a rifle marked .223 only.
Is the SIG Sauer M400 a good rifle?
The SIG M400 Tread is a reliable, accurate AR-15 platform priced under $800, making it a budget-friendly option. It performs well out of the box, suits beginners through competition shooters, and accepts standard AR accessories. Dependable and modular, though nothing distinguishes it from comparable rifles in its price range.
How much is the Sig Sauer M400 tread rifle?
Sig Sauer M400 Tread rifles, including the current M400 Tread V2, typically cost around $1,064 on our marketplace. Street prices for new rifles run approximately $999–$1,008, with some aggregators reporting average new prices above $1,100.
Can you shoot .223 and 5.56 the same?
You can safely fire .223 Remington in a 5.56 NATO rifle. However, never fire 5.56 NATO in a rifle marked .223 only—the NATO round's higher pressure can damage the chamber and barrel. Always check your rifle's chamber marking before loading.
Is the SIG M400 a pistol or rifle?
The SIG M400 comes in both rifle and pistol variants. The rifle features a standard-length barrel and stock, while the pistol has an 11.5-inch barrel with a stabilizing brace. Both are semi-automatic AR-15 platforms chambered in 5.56 NATO.
Is the SIG Sauer M400 an AR-15?
Yes, the SIG Sauer M400 is an AR-15 platform rifle. It uses direct impingement operation, chambers 5.56 NATO or .223 Remington, and features a 16-inch barrel with a collapsible stock. SIG offers multiple variants suited for range, competition, and defensive use.
What is the difference between the M400 and the M400 tread?
The M400 Tread is a refined, current-production version of SIG's M400 AR-15 platform, featuring an enhanced trigger, Magpul furniture, and a free-float handguard. The base M400 had simpler components. Specific differences vary by production year, so checking SIG Sauer's website for exact specifications is recommended.
How far does a SIGM400 shoot?
The SIG M400 in 5.56 NATO has an effective range of around 500 meters, though practical accuracy for most shooters falls between 100 and 300 yards. Actual range depends on ammunition, barrel length, and shooter skill.
