
Availability: In Stock
The Sig Sauer MCX-Spear in 6.8x51 is a civilian-market rifle built on the same platform the U.S. Army selected as its next-generation service rifle. With a 16-inch cold hammer-forged barrel, this semi-automatic rifle delivers the ballistic performance and reliability that defined a major shift in military small-arms capability—now available to American shooters and hunters. The 6.8x51 cartridge, paired with Sig's hybrid ammunition, achieves velocities exceeding 3,000 fps and represents a genuine leap in mid-to-long-range terminal performance.
What sets the MCX-Spear apart is its thoughtful engineering for serious use. The gas piston operating system with an adjustable, two-position gas valve keeps the action reliable across different ammunition loads and conditions. Ambidextrous bolt and catch releases, a non-reciprocating rear charging handle and side charging handle option, and fully ambidextrous controls make it equally at home for right- or left-handed shooters. The curved-profile Matchlite Duo trigger breaks clean, and the free-floating, M-LOK-compatible handguard gives you attachment points for lights, grips, and optics without binding the barrel.
The 16-inch barrel keeps the rifle handy in the field or at the bench, while the push-button folding Magpul SL-M stock collapses for transport or tight shooting positions. Coyote anodized receivers and a durable polymer grip round out a package that refuses to apologize for its military heritage. One 20-round AR-10 pattern magazine is included. The MCX-Spear also supports caliber conversions to 7.62x51, 6.5 Creedmoor, and 13-inch barrel options, so your platform investment can adapt as your needs evolve.
Built for precision, modularity, and dependability, the MCX-Spear is a purpose-built rifle for hunters and shooters who demand performance that matches its pedigree.
| Caliber | 6.8x51 |
| Barrel Length | 16 inches |
| Barrel Material | Cold Hammer-Forged Steel |
| Twist Rate | 1:7 |
| Muzzle Device | SLX/SLH QD Flash Hider (5/8"-24 threads) |
| Action Type | Semi-Automatic |
| Operating System | Gas Piston |
| Gas System | Adjustable (2-Position) |
| Trigger | Curved Matchlite Duo (Match-Grade) |
| Stock | Push-Button Folding Magpul SL-M (Telescoping) |
| Handguard | M-LOK Alloy (Free-Floating) |
| Grip | Polymer |
| Charging Handle | Non-Reciprocating Rear & Side Steel Options |
| Controls | Fully Ambidextrous (Bolt Catch & Release) |
| Magazine Type | AR-10 Pattern |
| Magazine Capacity | 20 rounds |
| Magazines Included | 1 (Steel) |
| Sights | Optics Ready (None Included) |
| Receiver Finish | Coyote Anodized |
| Accessory Rail | M-LOK |
| Overall Length | 38.3 inches |
| Overall Width | 2.5 inches |
| Height | 8 inches |
| Weight | 9.2 lbs (with magazine) |
This model is chambered in 6.8x51 with a 16-inch barrel. The 6.8x51 is a new-generation intermediate cartridge designed for superior performance and ballistics compared to traditional 7.62 NATO.
Yes. The MCX-Spear platform supports modular caliber conversions to 7.62x51 and 6.5 Creedmoor, as well as 13-inch and 16-inch barrel length options, so you can adapt the rifle to different missions over time.
The rifle uses standard AR-10 pattern magazines. One 20-round steel magazine is included with the rifle.
No. The MCX-Spear is optics-ready, meaning it's designed for mounting a scope or red dot of your choice. No iron sights or optics are included; you'll need to select and install your own.
Yes. The rifle features fully ambidextrous controls, including ambidextrous bolt and catch releases, rear and side non-reciprocating charging handles, and is equally suitable for left- and right-handed shooters.

SKU: 145480508 • Weight: 9oz



Availability: In Stock
The Sig Sauer MCX-Spear in 6.8x51 is a civilian-market rifle built on the same platform the U.S. Army selected as its next-generation service rifle. With a 16-inch cold hammer-forged barrel, this semi-automatic rifle delivers the ballistic performance and reliability that defined a major shift in military small-arms capability—now available to American shooters and hunters. The 6.8x51 cartridge, paired with Sig's hybrid ammunition, achieves velocities exceeding 3,000 fps and represents a genuine leap in mid-to-long-range terminal performance.
What sets the MCX-Spear apart is its thoughtful engineering for serious use. The gas piston operating system with an adjustable, two-position gas valve keeps the action reliable across different ammunition loads and conditions. Ambidextrous bolt and catch releases, a non-reciprocating rear charging handle and side charging handle option, and fully ambidextrous controls make it equally at home for right- or left-handed shooters. The curved-profile Matchlite Duo trigger breaks clean, and the free-floating, M-LOK-compatible handguard gives you attachment points for lights, grips, and optics without binding the barrel.
The 16-inch barrel keeps the rifle handy in the field or at the bench, while the push-button folding Magpul SL-M stock collapses for transport or tight shooting positions. Coyote anodized receivers and a durable polymer grip round out a package that refuses to apologize for its military heritage. One 20-round AR-10 pattern magazine is included. The MCX-Spear also supports caliber conversions to 7.62x51, 6.5 Creedmoor, and 13-inch barrel options, so your platform investment can adapt as your needs evolve.
Built for precision, modularity, and dependability, the MCX-Spear is a purpose-built rifle for hunters and shooters who demand performance that matches its pedigree.
| Caliber | 6.8x51 |
| Barrel Length | 16 inches |
| Barrel Material | Cold Hammer-Forged Steel |
| Twist Rate | 1:7 |
| Muzzle Device | SLX/SLH QD Flash Hider (5/8"-24 threads) |
| Action Type | Semi-Automatic |
| Operating System | Gas Piston |
| Gas System | Adjustable (2-Position) |
| Trigger | Curved Matchlite Duo (Match-Grade) |
| Stock | Push-Button Folding Magpul SL-M (Telescoping) |
| Handguard | M-LOK Alloy (Free-Floating) |
| Grip | Polymer |
| Charging Handle | Non-Reciprocating Rear & Side Steel Options |
| Controls | Fully Ambidextrous (Bolt Catch & Release) |
| Magazine Type | AR-10 Pattern |
| Magazine Capacity | 20 rounds |
| Magazines Included | 1 (Steel) |
| Sights | Optics Ready (None Included) |
| Receiver Finish | Coyote Anodized |
| Accessory Rail | M-LOK |
| Overall Length | 38.3 inches |
| Overall Width | 2.5 inches |
| Height | 8 inches |
| Weight | 9.2 lbs (with magazine) |
This model is chambered in 6.8x51 with a 16-inch barrel. The 6.8x51 is a new-generation intermediate cartridge designed for superior performance and ballistics compared to traditional 7.62 NATO.
Yes. The MCX-Spear platform supports modular caliber conversions to 7.62x51 and 6.5 Creedmoor, as well as 13-inch and 16-inch barrel length options, so you can adapt the rifle to different missions over time.
The rifle uses standard AR-10 pattern magazines. One 20-round steel magazine is included with the rifle.
No. The MCX-Spear is optics-ready, meaning it's designed for mounting a scope or red dot of your choice. No iron sights or optics are included; you'll need to select and install your own.
Yes. The rifle features fully ambidextrous controls, including ambidextrous bolt and catch releases, rear and side non-reciprocating charging handles, and is equally suitable for left- and right-handed shooters.
SKU: 145480508 • Weight: 9oz
