Over the past few years SIG has continuously developed the MCX platform for both US and international customers, including for the recently awarded US Army Next Generation Squad Weapon program. According to SIG CEO Ron Cohen one of their goals was to transition lessons learned from their defense work to commercial guns.

Consequently, taking these developments, SIG has has released a new version of the MCX rifle. Since it now has more in common with the SPEAR variant than VIRTUS, they have chosen to name it the SPEAR-LT. As you can see in the image below, MCX SPEAR-LT is really more of a family of firearms with pistol, carbine, and SBR options.

It is being released simultaneously in three calibers: .223, .300 BLK, and 7.62 x 39. The latter has long been promised but now it’s here and I’ve fired all three calibers. But it goes even further, with barrel length options. For the .223 and 7.62 x 39 versions, they offer 16” & 11.5” barrels while the .300 model is only available with a 9” barrel.

You’ll notice that the Coyote anodized finish like the XM5 MCX SPEAR but aesthetically the SPEAR-LT is slightly different from the earlier VIRTUS. This is most notable in the handguard (10″ or 13″) which is thinner and lighter, although, also more rigid. The 16″ variant is also about a pound lighter than its VIRTUS predecessor.

Additionally, there are two gas block positions, suppressed and unsuppressed and it comes outfitted with a SIG QD flash hider for compatibility with SIG suppressors.

They’ve also integrated the ambi bolt catch and a new folding stock mechanism from MCX designs for defense customers. The stock trigger is a flat blade match model but the new firing pin latch accepts standard AR triggers.

With the launch of the MCX SPEAR-LT, the VIRTUS model will cease production, but you’ll find a more advanced design with the latest features offered previously only to defense customers.

Below is SIG’s Press Release:

The Evolution of the SIG SAUER MCX: Introducing the MCX-SPEAR-LT

NEWINGTON, N.H., (September 19, 2022) – SIG SAUER is pleased to announce the evolution of the most advanced and tested rifle platform in the world with the introduction of the MCX-SPEAR-LT.  Built off the foundation of the MCX Virtus the third generation of the MCX combines all the extensive testing, continued product development, and customer/special operations feedback to become the MCX-SPEAR-LT.  

“The first generation of the MCX platform was designed to be an AR-15 style platform with added modularity.  The second generation of the MCX, the MCX Virtus, was purpose-built for rugged durability and brought unprecedented modularity.  Now comes the MCX-SPEAR-LT, which incorporates the best of both generations and is the culmination of the latest research, development, and innovation in the MCX platform,” said Tom Taylor, Chief Marketing Officer and Executive Vice President, Commercial Sales, SIG SAUER, Inc.  “The lightened handguard has the expected rigidity and durability of the MCX, the lower is a familiar SDI, M400-style lower and ambi-bolt catch and release that is designed to fit the legacy VIRTUS uppers for more versatility.  The MCX-SPEAR-LT will accept AR-15 style triggers, in addition to the legacy triggers for even more flexibility in the MCX platform.  With the MCX-SPEAR_LT also comes the long-awaited addition of the 7.62×39 caliber to the MCX family bringing even more modularity to a platform that simply can’t be matched.  The evolution continues and the MCX-SPEAR-LT has raised the bar for modular weapons technology.”

The MCX-SPEAR-LT rifle is an aluminum frame rifle with a gas piston operating system featuring a lightweight ergonomic handguard, push-button folding stock with cheek-rest, and a cold hammer forged carbon steel barrel available in 9-inch (300BLK), 11.5-inch (7.62×39 & 5.56), and 16-inch (7.62×39 & 5.56) lengths.  The rifle offers fully ambidextrous controls including bolt catch and release, a SIG QD suppressor-ready flash hider optimized for SIG SAUER QD suppressors, a SIG flatblade match trigger, comes optics ready and can be easily paired with a SIG SAUER Electro-Optics ROMEO8 or TANGO6T, and is finished in a Coyote Anodized finish.  The MCX-SPEAR-LT is available is 300BLK, 556 NATO, 762×39 calibers.


Caliber: 300BLK

Barrel Length: 9 inch

Caliber: 556 NATO

Barrel Length: 11.5 inch

Caliber: 762×39

Barrel Length: 11.5 inch

Caliber: 556 NATO

Barrel Length: 16 inch


Caliber: 762×39

Barrel Length: 16 inch

*For additional specs including weight, overall length, width, and height by model visit the product page at

The MCX-SPEAR-LT is now shipping and available at retailers.  To learn more about the MCX-SPEAR-LT or watch the product video visit

4 Responses to “SIG SAUER Launches MCX SPEAR-LT”

  1. Awesome weapon. My supervisor brought one to work today and I’m in love with it.

  2. AAA says:

    I think ill keep my AR yet again… (ACR, SCAR XCR-L and so many more)

  3. Stephen Vogel says:

    I’m curious if we’ll ever see the Ti internal rails they developed for this platform which were omitted for the masses. I hope its an option for us mere mortals down the line as it is for .gov