Sig Sauer

Sig Sauer MCX

Caliber 300 Blackout
Capacity 30 Rounds
Action Type Semi-automatic
Barrel Length 6.75"
Overview

About the Sig Sauer MCX

The Sig Sauer MCX is Sig Sauer’s modular, gas-piston-driven AR-pattern platform, chambered in 300 Blackout or 5.56 NATO with barrels from 6.75" to 11.5" and 10- or 30-round magazines, including the compact Rattler pistol-brace configurations, in black or flat dark earth. Its folding stock/brace and short barrel options make it one of the more compact platforms in this catalog. Ask Miami Guns which caliber and barrel length they currently have.

Specifications

Full Specs

Caliber300 Blackout
Capacity30 Rounds
Action TypeSemi-automatic
Barrel Length6.75"
Weight137 oz
Color / FinishBlack

Specs shown are for the most common configuration in stock. See all available configurations →

Configurations

Available Configurations

Miami Guns currently carries the Sig Sauer MCX in the following configurations. Tap a row to see a larger photo, and use the price button at the top of the page to check current pricing and availability.

SIG MCX RTLER 300BLK 6.75" BLK BRACE
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SIG MCX SPR 300BLK 9" FDE 30RD BRACE
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SIG MCX SPR 556 11.5" FDE 30RD BRACE
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SIG MCX SPR 556 11.5" FDE 10RD BRACE
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SIG MCX RATTLER 5.56 7.75" BLK BRACE

SIG MCX RATTLER LT 300BLK SBR 6.75"
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SIG MCX 300BLK SBR 9" 30RD FDE
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SIG MCX 556NATO 11.5" 30RD FDE SBR
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SIG MCX RATTLER SBR 556NATO 7.5" BLK
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Brand

Sig Sauer

Sig Sauer traces its roots to Swiss and German gunmaking traditions going back over a century, with its modern U.S. operations headquartered in New Hampshire. The P320 serves as the U.S. military's official M17/M18 sidearm, and Sig's broader lineup spans everyday-carry pistols, precision rifles, and modern sporting rifles.

Shop All Sig Sauer →
Buying Process

How Buying Works at Miami Guns

1

Check price & availability"See Price" opens current pricing and live in-stock inventory in our online store (or call us directly if a listing has no online link).

2

Choose where to pick upPick up at our Hialeah location serving the Miami area, or choose from over 2,000 other pickup locations nationwide.

3

Complete your background check & pick upWhen your order arrives, go in person to your chosen pickup location to complete the required background check (ATF Form 4473) and take it home.

Common Questions

Frequently Asked Questions

Yes — tap "See Price" above to check live availability in our online store and place your order. You can pick it up at our Hialeah location serving the Miami area, or at one of over 2,000 other pickup locations nationwide. If a listing has no online link, call us and we'll check stock directly.

A valid government-issued photo ID and a passed background check (ATF Form 4473), completed in person when you pick up your firearm. Firearms are never shipped to your home, so the same process applies at every pickup location.

It depends on your needs and comfort with the platform — our staff can walk you through fit and carry considerations in-store. For permit requirements, see our Concealed Carry Permit page.

See Price →