TFB Review: America’s New Battle Rifle – The SIG Spear in 6.8x51mm

It’s been almost a year since the NGSW program’s result was officially put into the field. The Army’s new XM7 (SIG MCX-SPEAR 6.8×51) has been the subject of a lot of discussion, derision, and intrigue, and I’ve not been immune to that curiosity. I’ve had the rare opportunity to run one of these rifles for the last couple of months, and since then, I’ve come a long way from my original assumptions about the rifle and its hybrid ammunition. Based on the last couple of months with the SIG Spear in its civilian configuration, I’d like to run you guys through a bit of the rifle’s history, as well as how it actually feels to shoot and run at the range.

More SIG Sauer Firearms @ TFB:

TFB Review: Original SIG Sauer MCX vs Spear LT Sig MCX LT in Limited-Edition Tigerstripe from the Sig Shorts Program TFB Review: SIG Sauer MCX-SPEAR 7.62×51 SBR

TFB Review: America’s New Battle Rifle – The SIG Spear in 6.8x51mm

The Next Generation Squad Weapon (NGSW) initiative began in 2017 with the Army focusing on growing concerns that the 5.56mm round lacked the reach and lethality necessary to counter modern and near-peer adversaries equipped with advanced body armor. At the beginning of the program, both the Army and the U.S. Government discovered that service members still preferred and loved the M4 Carbine platform in its developed forms.

Despite this sentiment, the program marched on after the Army concluded a set of assessments on the M4 platform and determined that the Next Generation Squad Weapons program would proceed. Thus, in December 2017 of 2022, the Army issued its set of requirements for the new rifle (NGSW-R).

Specifications:
The specifications for the prototype weapon systems are as follows:

NGSW-R

Caliber: 6.8mmWeight: 8.4 pounds; with suppressor, 9.8 poundsLength: 31 inches; 36 inches with suppressorBarrel length: 15.3 inchesRange: TBD

NGSW-AR

Caliber: 6.8mmWeight: 13.0 pounds; 14.5 pounds with suppressorLength: 36.75 inches; 41.9 inches with suppressorBarrel length: 17.5 inchesRange: TBD

In total, 6 designs were tested and evaluated over the next couple of years, with one design each from SIG Sauer, Textron Systems, and General Dynamics making the final cut. SIG Sauer was officially awarded the 10-year contract for both the XM5 (what the XM7 was called at the time) as well as the XM250 light machine gun in April of 2022. Just 11 months later the rifle was officially put to use by the US Army, being fielded first by the Army’s 1st Battalion, 506th Infantry Regiment of the pedigreed 101st Airborne. This selection obviously made a lot of bullpup fans understandably upset.

Rifle Specifications & Features

Product Link: https://www.sigsauer.com/mcx-spear-6-8-x-51.html

DetailsIn 2022, a historical announcement was made to officially select the MCX-SPEAR as the XM7 service rifle by the U.S. Army. In combination with the groundbreaking 6.8×51 hybrid ammunition, the MCX-SPEAR has become the pinnacle by which rifle capabilities will be judged.Capable of muzzle velocities in excess of 3,000 FPS with a 113gr bullet out of a 16” barrel, the MCX-SPEAR rifle is achieving the Army’s goal of advanced performance while also exceeding the requirements for durability. Now for the first time, this technology will be available to the U.S. civilian market with the MCX-SPEAR rifle chambered in 6.8×51 along with a family of Hybrid Ammunition from SIG SAUER. The MCX-SPEAR platform also offers a new level of modularity, allowing for caliber conversion between 6.8×51, 7.62×51 and 6.5 Creedmoor and 13” or 16” barrel length options. In addition, the MCX-SPEAR features a non-reciprocating side charging handle, a rear charging handle, fully ambidextrous controls, a 2-Stage Match Duo Trigger and a free-floating M-LOK™ handguard.For the first time in more than 30 years a new rifle has brought an entirely new level of performance and reliability to the U.S. Army, and is now ushering in a changing of the guard.

SIG MCX-SPEAR FEATURES:

Civilian model based on U.S. Army’s Next Generation Squad Weapon (NGSW) XM7 RifleAmbidextrous Bolt/Catch Release2-Stage Match Trigger Non-Reciprocating Side Charging HandleSteel Rear Charging HandlePush-Button Folding/Telescoping Magpul SL-M StockFree-Floating M-LOK Handguard with Easily Adjustable 2 Position Gas ValveCLUTCH-LOCK QD Flash HiderSIG SAUER Made, Steel Magazine

The average going price for one of these rifles right now is about $5,700 from what I’ve gathered online. Ammunition is similarly as expensive.

Rifle Handling

Anyone who has handled an M4 or virtually any civilian AR-15 carbine will instantly recognize that the SPEAR is a heavy beast of a rifle. In stark contrast to the relatively lightweight AR, the SPEAR along with its hybrid cased 6.8x51mm cartridge is quite heavy at nearly 9-½ lbs while its ammo is on average anywhere between 20-30% heavier depending on the specific loading. For this review, SIG provided me with one ammo can (460 rounds) of 113-grain Hybrid Ball ammunition which I presume is what the XM250 will use as its standard linked ammunition. The heavier ammunition naturally means you’ll be able to carry less of it for the same load or simply just need to carry more weight around.

My first couple of outings with the XM7 were all about getting a feel for its handling during offhand shooting, prone shooting, reloading, unloading, and general handling. Although the XM7 is quite heavy, it isn’t too difficult to shoot from a shouldered position if you’re in decent shape—especially after a few practice sessions. Recoil management follows a similar pattern. In the footage I’ve captured, many shooters initially seem surprised by the rifle’s recoil. After firing a few rounds, however, most of them naturally adjust their stance. This tendency to adapt on the fly suggests that the Army will likely need to modify its marksmanship training to account for the increased recoil of the 6.8x51mm cartridge. Overall the weight of the rifle and the recoil impulse ended up mattering a lot less to me after I had some one-on-one time with the rifle.

With nearly the entire case of ammo down range, I’ve come to the conclusion that what is most jarring about the rifle handling is where most of the weight is. The XM7’s short-stroke gas piston system negates the need for a buffer tube and also gives the rifle superior handling of gasses even without the aid of SIG’s dedicated suppressor for the platform. However, the deletion of so much weight towards the rear of the rifle, combined with the added weight of an optic, LAM, light, and bipod makes the rifle extremely front-heavy. While this isn’t a problem for me at the range, I can definitely see the extremely forward-heavy nature of the rifle being a source of quick fatigue for soldiers in the field needing to shoot from an unsupported position. In fact, this is something I experienced first-hand by running the 5.56 Spear LT at a night vision competition – the front heaviness of the rifle does a lot to fatigue any shooter.

Mostly Ambidextrous

The ambidextrous controls are a mixed bag for me of positives and negatives. The side charging handle in particular is both a blessing and a curse. On the one hand, it provides you with a large, easily accessible way to clear malfunctions or clear the rifle. While it is non-reciprocating it is easy to forget that if it is left in the rearward position during a manual lock-back, it will come forward if you charge the rifle using either of the ambidextrous bolt lock/release mechanisms and this could potentially lead to a nasty collision with your hand. Left-handed shooters do not equally benefit from the inclusion of this left-side charging handle and are left to work with the almost useless AR-15-style ambidextrous charging handle which is particularly hard to access if you’ve got an optic mounted to the rifle. I’ve personally watched a number of people inadvertently get their hands smacked just messing around with the rifle so be wary!

Apart from the charging handle and ejection side, the rest of the rifle is virtually 100% ambidextrous and uses SIG’s standard set of ambi controls which I’ve come to love since I first started playing around with the  SIG M400 SDI. Combined with the larger side charging handle, the relatively stiff operation of the SPEAR is made much easier with the ambi controls once you’ve become accustomed to them.

Accuracy

Although many will look at the XM7 and instantly conclude that it’s a sniper rifle, I personally think this couldn’t be any further from the truth. Given the specifications put out by the NGSW and all of the performance metrics I’ve seen from early reporters in the field, the XM7 is very clearly a modern Battle Rifle. As with a lot of weapons systems, the Military’s accuracy requirements for the XM7 aren’t quite as high as you’d expect and the requirements in the NGSW called for 4MOA accuracy.

I used two different types of ammunition including the  113gr ball ammo as well as some of SIG’s 155-grain Hybrid Match ammo. Out of the two groups I shot it’s clear that the 113gr ball ammo isn’t up to the 4MOA task in my hands in the rifle’s current configuration. My chronograph data from the same 12-round group (2 loose rounds) that I shot shows an extreme spread of only 41.6 FPS which isn’t really all that bad and doesn’t necessarily tell me that the group size is entirely the fault of the ammo. However, a 5MOA group still doesn’t meet the military’s 4MOA requirements. I’m typically more prone to blaming myself for groups that don’t meet manufacturer’s standards but the 155-grain Hybrid Match ammo fared much better with a 2.5 MOA group. The 155-grain match ammo also showed much better results from the chronograph with a standard deviation of just 10.3 fps and an extreme spread of 34.5 fps.

It Needs a Suppressor

The main drawback of the 6.8x51mm hybrid case is not just the cost of the cartridge – it’s also really loud even out of a 16” barrel. However, as with all of the NGSW submissions, the XM7 included a suppressor as part of the weapon system in the form of the NG68SPEAR. As reducing lead and toxic gas exposure has been a higher priority for the military, NG68SPEAR is designed to drastically reduce both of those and SIG claims that the SLX reduces gas port gas exposure by up to 80%. Unfortunately, I wasn’t able to secure the matching suppressor (or the fancy Vortex contract optic) and this is a shame because shooting nearly 500 rounds of 6.8x51mm for this review was probably the loudest experience I’ve had reviewing a firearm for TFB. A suppressor is almost a requirement for this version of the rifle and mine isn’t even the military-issue 13” barrel variant which would undoubtedly be much louder at the muzzle.

If you do find yourself lucky enough to have one of these rifles and you don’t feel like using the correct SIG Sauer suppressor, it is possible to mount other suppressors via a  SIG Taper Cap. This 5/8×24 adapter is $15 directly from SIG and provides a nice clean 90° surface for your non-tapered muzzle device to torque against. This would allow you to use my only other recommended suppressor for the 6.8x51mm variant of the SPEAR – the CAT ODB 718. With pressures tickling 85k PSI, I can’t in good faith recommend any other suppressor aside from the dedicated 6.8 offering SIG has put out. However, if you’re dead set on using another suppressor there is indeed a way to do it.

Final Thoughts

With the XM7 in 6.8x51mm, the Army has stepped back into the world of battle rifles. The new cartridge in particular gives soldiers improved range, accuracy, and armor penetration beyond the capabilities of 5.56mm while still giving them a platform that can fill the role of an infantry rifle – albeit not as well as the M4 did in my opinion. Those that I have talked to who have more extensive experience with the rifle have said that they notice the added heft, particularly at the front of the rifle once optics and accessories are mounted, and most of them feel that marksmanship training will need to adapt for the stronger recoil impulse and overall weight and ammunition capacity restrictions that the new cartridge and rifle require.

Despite these trade-offs, the XM7’s short-stroke piston system, ambidextrous controls, and modular design demonstrate a forward-thinking approach to the concerns of the modern U.S. Military and despite what I think about it on a personal level – the rifle and cartridge are impressive and it’s honestly quite exciting to see the U.S finally adopt a new service weapon. It’s neither a “sniper rifle” nor just another AR variant; instead, it perfectly fits within the niche of a true battle rifle, bridging the gap between intermediate and full-power cartridges in a way that we haven’t seen before since probably the M14 EBR. Interested to hear your thoughts on this one – Would you ever consider picking one of these up, even if just for the historical value?

SIG Sauer MCX-SPEAR 6.8X51

https://www.avantlink.com/click.php?tt=cl&mi=10077&pw=202211&ctc=10077&url=https%3A%2F%2Fwww.brownells.com%2Fguns%2Frifles%2Fsemi-auto-rifles%2Fmcx-spear-6.8x51mm-semi-auto-rifle%2F

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