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Sig Sauerar-15Value Tier

Sig Sauer M400 Forge Pistol

11.5" AR pistol variant of the M400 Forge with Magpul BSL arm brace and chrome-lined bore

Price
$1,000
Weight
6 lb 3 oz
Calibers
5.56x45mm
Rail
mlok

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Key Highlights

  • •Chrome-lined hammer forged 11.5" barrel
  • •Factory TriggerTech duty trigger and Romeo MSR Gen II included
  • •Magpul BSL pistol stabilizing arm brace

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Palmetto State Armory

Sig Sauer M400 FORGE 11.5" 5.56 NATO AR Pistol w/ Romeo MSR, Black

$1000.99
Unknown
3h ago
View offer

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Overview

The Sig M400 Forge Pistol takes the same duty-ready component stack as the 16-inch rifle - factory TriggerTech duty trigger, Breek Arms Warhammer ambidextrous charging handle, Romeo MSR Gen II red dot, and Sig's Infinite Guarantee - and repackages it into an 11.5-inch AR pistol platform. The shorter barrel uses a chrome-lined bore with external FMC coating to handle the higher heat and pressure of a carbine-length gas system on a sub-16-inch tube. A Magpul BSL pistol stabilizing arm brace replaces the SL-K stock, and the handguard drops to 10 inches of free-float M-LOK real estate.

At 6.2 pounds and 27.8 inches collapsed, the Forge Pistol targets the home-defense, vehicle-ops, and suppressor-host segment where a 16-inch rifle is unwieldy but an SBR tax stamp is unwanted. Keeping the pistol classification via the Magpul BSL brace avoids NFA paperwork while retaining most of the handling benefits of a short-barrel configuration. The factory-mounted Romeo MSR Gen II red dot is well-matched to the intended ranges, and the TriggerTech duty trigger eliminates the single most common upgrade cycle on AR pistols in this price bracket.

Key Features

  • 11.5" chrome-lined hammer forged barrel with external FMC coating
  • Carbine-length direct impingement gas system
  • 1:7 twist rate
  • Factory TriggerTech duty trigger - two-stage flat blade, 3.5 lb
  • Breek Arms Warhammer ambidextrous charging handle
  • Sig Romeo MSR Gen II red dot included (2 MOA)
  • 10-inch free-float M-LOK aluminum handguard
  • Magpul BSL pistol stabilizing arm brace
  • Ambidextrous safety selector and magazine release
  • A2 birdcage flash hider (1/2x28)
  • Sig Infinite Guarantee (lifetime, transferable)

Capability Profile

0-10 Scale Across 8 Axes

Pros

  • +Same premium component stack as the 16" rifle in a compact package
  • +Chrome-lined bore handles short-barrel heat better than FMC-only
  • +Factory-mounted Romeo MSR Gen II red dot
  • +Magpul BSL brace keeps it pistol-classified (no NFA)
  • +Lightweight at 6.2 lbs with brace folded
  • +Infinite Guarantee covers rifle and optic

Cons

  • −Carbine-length gas is more abusive on components than mid-length
  • −10-inch handguard limits accessory real estate vs 15" rifle
  • −Left-side-only bolt release
  • −Flash and report from 11.5" unsuppressed is significant

Detailed Specifications

caliber
5.56 NATO
Barrel Length
11.5 inches
Overall Length
27.8" collapsed / 29.8" extended
weight
6.2 lbs
Gas System
carbine-length
Twist Rate
1:7
barrel
Chrome-lined hammer forged, external FMC coated
handguard
10-inch free-float M-LOK alloy
trigger
TriggerTech duty, two-stage flat, 3.5 lb
stock
Magpul BSL pistol stabilizing arm brace
sku
PM400-556N-11B-FORGE

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Compatibility Tags

family: modern-riflefamily: ar-patterntrigger: ar-fcginterface: picatinny-tophandguard: mlokbarrel: compactthread: 1/2x28mag-type: stanagreceiver-pattern: ar-15

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