TFB Review: SIG MCX Spear LT

The world of tactical rifles is a sea of new products both in the AR15 market and the AR alternatives group. One of the major products to come onto the market in recent years is the MCX line of rifles from SIG. The latest generation is a lighter and updated system. I was browsing the interwebs and decided to snag one of the new 11.5” Spear LTs and after some time with this new variant, I can give you my fair shakedown of the updated MCX. Let’s take a closer look at the new SIG MCX Spear LT.

Specs 

The first noticeable difference between the previous Virtus model and the Spear LT is the change from their dark grey color pattern to a metallic coyote brown. Picking up the firearm immediately shows the weight reduction on the Spear LT from the previous generation Virtus. The handguard on the new Spear LT is profiled differently and is considerably lighter than the previous generation. Another improvement from older models is SIG’s new flat blade trigger they put into the Spear LT. With the Spear LT being a short-stroke gas piston system, the piston comes with two settings for shooters to use. The first is a normal gas setting that should work with all ammo when the firearm is clean and properly maintained. The other setting is an adverse setting that is mainly used when the rifle hasn’t been properly maintained. In the past, I have also used this setting for low-pressure rounds that may not cycle using the normal setting.

SIG offers the new Spear LT in a number of barrel configurations and calibers. I decided on the 11.5” 5.56 variant but they also have 300 Blackout and 7.62x39mm. Other features on the Spear LT include fully ambidextrous controls as well as easy interchangeable barrels so you can pull the barrel and handguard quickly to make any length desired. As Standard, SIG Rocksetts their QD flash hider that works with their suppressor. SIG is shipping their Spear LTs to dealers currently and the MSRP for the 11.5” model I picked up is $2,729.99.

Specs List 

MSRP$2,729.99ManufacturerSig SauerManufacturer Part #PMCX-556N-11B-LTModelMCXModelSPEAR-LTActionSemi-automaticTypeARCaliber556NATOBarrel Length11.5″ColorCoyoteGripsSig SauerCapacity30 RoundsSubcategoryOther HandgunsMaterialAluminumFinishAnodized

Range Time

During the last couple of months with the SIG Spear LT, I have put roughly 1,100 rounds with a mixture of rounds. I ended up filing the paperwork to SBR for the 11.5” Spear which really allows me to use it as intended with a folding stock. I also threw on the Ground Combat Solutions Modular Vertical Grip. Throughout my range of trips with the Spear LT, there are several features I prefer over the previous Virtus models. The handguard profile and weight difference are immediately noticeable. The redesigned handguard was a big improvement in the overall feel when shooting in your hand but the weight savings also change the center of gravity of the rifle making it much more balanced.

The Virtus rifles can start to feel a bit front-heavy whereas the new Spear LT makes it easier to transition targets and manipulate the gun. The flat blade trigger is crisp with an audible reset. My example has right around an 8 lbs trigger which is a bit heavier than I like but it’s still a very good crisp predictable trigger. For the duration of my testing, I left the gas block in the normal position without cleaning or adding extra lubricant. The ability to throw a folding stock on a shorter gun really does make it feel like a full-size rifle in a compact package. The short-stroke piston isn’t as smooth as a direct impingement system but the recoil is still light and very predictable.

Accuracy and Reliability

I used some SIG Match 77gr ammunition which the rifle can handle with its 1:7″ twist rate. I shot roughly 5 different groups of 5-shot groups to see what the overall accuracy would be. With match grade ammo, I was getting an average group of 1.35-1.44” and with regular 55gr PMC ammunition I was getting a wider group of 1.86-2.05”. Out of a short-barreled rifle, I find these groups more than acceptable even with the standard run-of-the-mill ammunition. I think with a slightly lighter trigger I could have had a slightly tighter group but it’s still a very good combat trigger.

When it comes to reliability, the SIG MCX Spear LT has been completely reliable using factory ammunition even with no cleaning for the initial 1,000 rounds of testing. This isn’t exactly surprising since this is what should be expected from a rifle that costs more than $2,500 but it’s still good to see the SIG has been completely reliable even during extended durations without cleaning. With modern technology and high-quality machining processes, we are seeing less of malfunctions right out of the box but of course, there are always issues with particular models. I am happy to report though that my example has been 100% reliable with no issues.

Suppressor Options 

There are a number of choices on the market today that offer not only sound suppression but also cut down on back pressure so you do not have to deal with any excess gas coming back into your face. The short-stroke piston system on the Spear LT makes it incredibly easy to suppress and helps cut down on a large portion of the excess coming back into the shooter’s face. The Spear LT comes standard with SIG’s flash hider already set up to take the SIG line of suppressors. That’s the natural path to go if you don’t have a suppressor before buying the firearm. Some of us already have suppressors or want to shoot a suppressor on multiple firearms. I put together two options that would be great choices for this rifle, so let’s take a look at some of those options.

SIG SLX Suppressor

The easiest option for the MCX Spear LT is the SIG SLX line of suppressors. The 556QD model will allow you to use a suppressor without any changes to the Spear LT. The SLX line of suppressors was made for the US military but is now available to the civilian market as well. The big selling point besides sound suppression with the SLX is the fact it cuts down almost 80% of the backpressure and gas coming back at the shooter.

The QD feature allows shooters to simply use the flash hider that SIG provides and quickly attach the suppressor without issue. Other features like the end cap of the suppressor can be replaced but the body of the suppressor only has one piece removing the older style baffle system for a more modern one-piece design. This allows the gas to work through and creates an overall higher level of reliability. THE SLX line of suppressors is the easiest choice for people new to suppressors and is a great option for MCX users.

Weight: 19ozLength: 7.4″Caliber Rating: .223/556mmMaterials: InconelSuppressor BodyClutch-LOK QD MountInstructions

You can buy this suppressor at Silencer Shop through the link below:

Huxwrx Flow 556K Suppressor

Another fantastic choice is the Huxwrx Flow 556K line of suppressors. These suppressors just like the SIG suppressors cut down on gas and fumes coming back in the face of the shooter. The Huxwrx Flow 556K suppressor is a 3D-printed single-piece suppressor offering sound suppression, a reduction in blowback gasses as well as flash reduction to keep your signature low. In my personal experience, this suppressor has a low weight on the barrel keeping the overall weapon profile similar to what it feels like without a suppressor. The overall lack of carbon and debris that comes back is really worth having a flow-through suppressor. The MCX has a short-stroke piston which eliminates 95% of this but it’s still an overall improvement from a traditional baffle suppressor. 

Overall Thoughts

My time with the MCX Spear LT has been really a positive one. I have the first-generation Rattler and this MCX Spear LT has a number of refinements from the handguard design to overall weight distribution. It may be something different from an AR-15 but it certainly has its benefits. If you are looking for a truly capable rifle, the MCX Spear LT is a great option. I plan on keeping mine for the foreseeable future and will give you an update after I have even more rounds through it.

 Do you have experience with the Spear LT? If you do, I would love to hear your experiences with them in the comments below. If you have questions about the Spear LT or other firearms, be sure to shoot me a message on Instagram @fridgeoperator. Stay safe out there and we will see you next time in the next review.