11.5" AR pistol variant of the M400 Forge with Magpul BSL arm brace and chrome-lined bore
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Sig Sauer M400 FORGE 11.5" 5.56 NATO AR Pistol w/ Romeo MSR, Black
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.
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