SIG Sauer Rifles
SIG Sauer M400
Specs, variants & prices
SIG Sauer currently offers the M400 rifle, chambered in 5.56 NATO and .223 Rem. Retailers carry 14 factory configurations, and you'll find every one in the table below. Barrels run from 11.5" to 16". Of the 14 versions, one ships with a ROMEO-5 installed. SIG Sauer's suggested retail prices run from $999.99 to $1,749.99, and stores set their own prices from there.
What versions of the SIG Sauer M400 are there?
14 current versions. Specs and measurements are SIG Sauer's own.
M400 ROSE
2x 30rd magazines
- Optics
- Model / part #
- RM400-16B-ROSE-R5X2
- Caliber
- 5.56 NATO
- Capacity
- 30
- Barrel
- 16"
- Overall length
- 36.5"
- Weight
- 7.0 lb
- Finish
- Black Anodized
- MSRP
- $999.99
- CA
- —
- Status
- Current
M400-FORGE
1x 30rd magazines
- Optics
- Model / part #
- RM400-556N-16B-FORGE
- Caliber
- 5.56 NATO
- Capacity
- 30
- Barrel
- 16"
- Overall length
- 35.5"
- Weight
- 6.8 lb
- Finish
- Black Anodized
- MSRP
- $999.99
- CA
- —
- Status
- Current
M400-FORGE
1x 10rd magazines
- Optics
- Model / part #
- RM400-556N-16B-FORGE-10
- Caliber
- 5.56 NATO
- Capacity
- 10
- Barrel
- 16"
- Overall length
- 35.5"
- Weight
- 6.8 lb
- Finish
- Black Anodized
- MSRP
- $999.99
- CA
- —
- Status
- Current
M400-FORGE
1x 30rd magazines
- Optics
- Model / part #
- RM400-556N-16B-FORGE-CON
- Caliber
- 5.56 NATO
- Capacity
- 30
- Barrel
- 16"
- Overall length
- 35.5"
- Weight
- 6.8 lb
- Finish
- Concrete Gray Cerakote
- MSRP
- $999.99
- CA
- —
- Status
- Current
M400-FORGE
1x 30rd magazines
- Optics
- Model / part #
- RM400-556N-16B-FORGE-FDE
- Caliber
- 5.56 NATO
- Capacity
- 30
- Barrel
- 16"
- Overall length
- 35.5"
- Weight
- 6.8 lb
- Finish
- FDE Cerakote
- MSRP
- $999.99
- CA
- —
- Status
- Current
M400-FORGE
1x 30rd magazines
- Optics
- Model / part #
- RM400-556N-16B-FORGE-MSGRN
- Caliber
- 5.56 NATO
- Capacity
- 30
- Barrel
- 16"
- Overall length
- 35.5"
- Weight
- 6.8 lb
- Finish
- Moss Green Cerakote
- MSRP
- $999.99
- CA
- —
- Status
- Current
M400-SDI SENTRY
1x 30rd magazines
- Optics
- Model / part #
- RM400-SDI-16B-R5FX
- Caliber
- 5.56 NATO
- Capacity
- 30
- Barrel
- 16"
- Overall length
- 36.5"
- Weight
- 8.0 lb
- Finish
- Black Anodized
- MSRP
- $1,749.99
- CA
- —
- Status
- Current
M400-SDI X
1x 30rd magazines
- Optics
- Model / part #
- RM400-SDI-16B-FDE
- Caliber
- 5.56 NATO
- Capacity
- 30
- Barrel
- 16"
- Overall length
- 36.5"
- Weight
- 7.0 lb
- Finish
- FDE Cerakote
- MSRP
- $1,499.99
- CA
- —
- Status
- Current
M400-SDI X
1x 30rd magazines
- Optics
- Model / part #
- RM400-SDI-16B-MSGRN
- Caliber
- 5.56 NATO
- Capacity
- 30
- Barrel
- 16"
- Overall length
- 36.5"
- Weight
- 7.0 lb
- Finish
- Moss Green Cerakote
- MSRP
- $1,499.99
- CA
- —
- Status
- Current
M400-SDI X
1x 30rd magazines
- Optics
- Model / part #
- RM400-SDI-16B-P
- Caliber
- 5.56 NATO
- Capacity
- 30
- Barrel
- 16"
- Overall length
- 36.5"
- Weight
- 7.0 lb
- Finish
- Hard Coat Anodized
- MSRP
- $1,499.99
- CA
- —
- Status
- Current
M400 Forge 5.56 AR-15 Rifle
1x 10rd magazines
—- Optics
- Model / part #
- RM400-556N-16B-FORGE-CA
- Caliber
- 5.56 NATO
- Capacity
- 10
- Barrel
- 16"
- Overall length
- —
- Weight
- 7.2 lbs
- Finish
- Black
- MSRP
- —
- CA
- Yes
- Status
- —
M400 Rose .223 Rem AR-15 Rifle
2x 10rd magazines
—- Optics
- Model / part #
- RM400-16B-ROSE-R5X2-10
- Caliber
- .223 Rem
- Capacity
- 10
- Barrel
- 16"
- Overall length
- —
- Weight
- 6.4 lbs
- Finish
- Black
- MSRP
- —
- CA
- —
- Status
- —
M400 SDI 5.56 AR Pistol
1x 30rd magazines
- Optics
- Model / part #
- PM400-SDI-11B-FDE
- Caliber
- 5.56 NATO
- Capacity
- 30
- Barrel
- 11.5"
- Overall length
- —
- Weight
- 5.9 lbs
- Finish
- Flat Dark Earth
- MSRP
- —
- CA
- —
- Status
- —
m400 Sig ROMEO5 5.56 AR-15 Rifle
2x 10rd magazines
- Optics
- Factory dotROMEO-5 installed
- Model / part #
- RM40016BROSER5X210
- Caliber
- 5.56 NATO
- Capacity
- 30
- Barrel
- 16"
- Overall length
- —
- Weight
- —
- Finish
- Black
- MSRP
- —
- CA
- —
- Status
- —
What calibers does the M400 come in?
It's chambered in 5.56 NATO and .223 Rem, depending on the version.
Is the M400 optics-ready?
Of the 14 versions, one ships with a ROMEO-5 installed. Some of these optics details come from a retailer listing rather than from the maker.
How much does a SIG Sauer M400 cost?
SIG Sauer's suggested retail prices run from $999.99 to $1,749.99, depending on the version. Tap “See prices” next to any version to see what retailers are asking.
Can you buy one in California or Massachusetts?
According to SIG Sauer, one version is available in California, but none in Massachusetts. Look for “Yes” in the CA and MA columns. State rules change, so check our California and Massachusetts pages before you buy.
What's the latest on the M400?
Nothing new on the M400 lately.
Specs from SIG Sauer, checked October 22, 2026 (source). SIG Sauer doesn't publish part numbers or UPCs, so those, along with the list of factory configurations, come from retailer listings. Each deals page links to its source. Spot a mistake? Let us know and we'll fix it. SIG Sauer is a trademark of its owner, listed for identification only. Firearms Almanac isn't affiliated with SIG Sauer.