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0122-22 Product Spot Light - Sig Sauer MCX Spear_Thumb

Product Spotlight: SIG MCX Spear Next-Generation Battle Rifle

Author Caleb Savant
one year ago

In April 2022, the U.S. Army announced that the SIG Sauer MCX Spear had won the Next Generation Squad Weapon (NGSW) trials. Our Caleb Savant got his hands on a civilian version of the new Spear, and he gives us a tour, assessing the rifle from both a gunsmith's perspective AND a combat veteran's.

The Spear is chambered in the new .277 SIG Fury (6.8x51mm) cartridge, which is a .308 Winchester / 7.62 NATO case necked down to 6.8mm with a steel base at the bottom, which allows for a much higher operating pressure: 80,000 psi vs the 308's 62,000 psi! Even with its 13" barrel, the MCX Spear is flatter shooting than a 6.5 Creedmoor out to 1,000 yards, and it delivers 30% more energy on impact.

Does that extra power bring a weight penalty on the rifle? Contrary to what you might've read on the Interwebs, the Spear actually weighs LESS than an HK417. The Spear's short-stroke piston operating system means there's no need for an AR-15 type buffer system, so a folding stock is standard equipment.

Controls are very similar to the M4 but fully ambidextrous, with a traditional AR-15 ambi charging handle AND a non-reciprocating charging handle on the left side of the rifle. The extra leverage the side charging handle provides will be a big help in clearing malfunctions.

Remember that recent Smyth Busters video where Caleb came out strongly "pro" forward assist? Well, the MCX Spear retains the forward assist! The Spear has an ambi safety selector, match-grade 2-stage trigger, ambi magazine release, and a standard M4 bolt release with corresponding ambi lever on the right side. A steel insert reinforces one of the M4's weak spots, the raceway for the bolt carrier's cam. The insert is easy to replace, thus greatly extending the upper receiver's service life.

The upper receiver's MIL-STD 1913 top rail cantilevers far over the barrel before it meets up with the handguard. Simply remove two bolts to change the barrel. Just by swapping the barrel, the MCX Spear can be turned into a 7.62 NATO or 6.5 Creedmoor rifle. An easy-access adjustment knob on the gas block lets the operator switch between "NORMAL" and "ADVERSE" gas flow.

Unlike the permanently over-gassed M4, the Spear can be switched to over-gassing only when necessary. The SLX MG suppressor is attached via SIG's clutch-lock system. To keep the SLX MG compact enough and still have proper baffling to do its job, it's 3D printed from extremely heat- and pressure-resistant Inconel alloy. It produces far less gas blowback toward the shooter than a standard M4 suppressor. Remove the SLX, and there's a simple but effective flash hider underneath that really kills the flash from the extra gas exiting out the front of the suppressor.

The MCX Spear comes with translucent polymer magazines made by Lancer Systems, but it will function just fine with standard SR-25 7.62 NATO magazines, too.