Good evening everyone and welcome back to TFB’s Silencer Saturday brought to you by Yankee Hill Machine, manufacturers of the new YHM Turbo T3 5.56 rifle suppressor. Last week we discussed the SIG Sauer MCX-SPEAR – a 13″, 7.62×51 mm piston rifle. This week we take its little brother out on the range: the 16″ SIG MCX-SPEAR LT in 5.56×45 mm paired with the SIG SLX556-QD suppressor. Let’s take a look at how it performed.
SILENCER SATURDAY #270: On The Range – SIG MCX-SPEAR LT And SLX556-QD
More SIG MCX-SPEAR @ TFB:
SILENCER SATURDAY #270: On The Range – SIG MCX-SPEAR LT And SLX556-QD
SILENCER SATURDAY #270: On The Range – SIG MCX-SPEAR LT And SLX556-QD
Currently, this SIG MCX-SPEAR is the only 16″ 5.56 rifle I own. No, I’m not some sort of NFA snob – after our discussion on short barrels a few weeks ago you should have a good idea about choosing optimal lengths for different cartridges. Personally I think 16″ 5.56 rifles only exist because of the National Firearms Act of 1934. Otherwise we would have a lot of 12.5″ and 18″ rifles with a few outliers thrown in there for spice.
But honestly, I’m not complaining; the extra barrel length over the 11.5″ variant along with the highly efficient SIG SLX556-QD made for smooth and “quiet” shooting. As a reminder, no 5.56mm rifle will be truly hearing safe. But in the name of science, I did remove my left ear plug for a few shots and found the report to be equivalent to an unsuppressed .22LR rifle. I kept the gas on the restricted (-) setting for todays testing and the MCX-SPEAR LT functioned perfectly.
SILENCER SATURDAY #270: On The Range – SIG MCX-SPEAR LT And SLX556-QD
The QD in the model name stands for quick disconnect and the SLX and SLH QD system is referred to as Clutch-Lok. It is one of the best QD systems on the market, featuring a right hand thread on the mount and in the suppressor and short 1/24 turn of a ring from unlocked to locked. It’s solid with zero play of movement. It is heavier and slightly more bulky than other market options, but it is absolutely rock solid.
The SLX and SLH line from SIG are manufactured using additive manufacturing processes (3D Printing), are constructed with either Inconel or Titanium, and are designed to vent gases and debris forward by alieviating a pressure differentia inside the tube. That pressure, seen in more traditional silencers, can cause blowback of gases into the action as well as back into the shooters face.
SIG SLX556-QD
- Model: SLX556-QD
- Manufacturers Page: https://www.sigsauer.com/slx-suppressor.html
- Caliber: 5.56 NATO
- Material: Inconel
- Diameter: 1.67 in (42 mm)
- Length: 7.4 in (188 mm)
- Weight: 19.4 oz (550 g)
- Mount: Clutch-Lok QD
SILENCER SATURDAY #270: On The Range – SIG MCX-SPEAR LT And SLX556-QD
There has been some discussion of the MCX-SPEAR handguards shifting from putting pressure on one side or the other. I tightened the two retaining screws that lock the handguard to the receiver and haven’t noticed any shift when confirmed with a rail mounted laser. I used an ARCA rail attachment to mount to my Really Right Stuff tripod and also didn’t observe any shift at the end of the day. The retaining screws may come a little loose from the factory but tightening them to 35 or 40 in/lbs seems to be the sweet spot. That’s inch pounds, NOT foot pounds. Here’s a friendly reminder to read your owners manual.
SIG MCX-SPEAR LT
Features:
- 13” Lightweight Ergonomic Handguard
- SIG Flatblade Match Trigger
- Fully Ambidextrous Controls
- Interchangeable Barrels
- Push-Button Folding Stock With Cheekrest
- SIG QD Suppressor-Ready Flash Hider
Specifications:
- SKU: RMCX-556N-16B-LT
- Manufacturers Page: https://www.sigsauer.com/firearms/rifles-pistols/sig-mcx.html
- Owners Manual: https://www.sigsauer.com/media/sigsauer/resources/OPERATORS-MANUAL-MCX-SPEAR-LT-2402988-01-REV00-WEB-FILE.pdf
- MAP Pricing: As low as $2499
- Caliber: 5.56 NATO
- Frame Material: Aluminum
- Frame Finish: Coyote Anodized
- Barrel Material: Cold Hammer Forged Carbon Steel
- Barrel Finish: Nitride
- Magazine Capacity: 30 Rounds
- Sights: Optics Ready
- Trigger: Flat Blade Match
- Measurements:
- Overall Length: 34.3 in / 870mm
- Overall Height: 7.8 in / 197mm
- Overall Width: 2.8 in / 71mm
- Barrel Length: 16 in / 406.4mm
- Barrel Twist: 1:7 in / 1:177.8mm
- Weight W/Magazine: 7.4 lb / 3.4 kg
SILENCER SATURDAY #270: On The Range – SIG MCX-SPEAR LT And SLX556-QD
I pulled from an old stash of Federal Premium Gold Medal 73gr OTM Berger bullet for today’s testing. I have a few more match loads coming in to see what the MCX-SPEAR LT barrel prefers. But this is a quality round suitable for some initial accuracy testing. I’m also using some stainless steel magazines from DURAMAG which have always performed perfectly for me in the MCX. They just sent me some 7.62 stainless steel magazines for testing in the MCX-SPEAR that we will see here in a few weeks.
Yes, this rifle looks goofy with the 6-24X optic, but it gets the job done.
All shots were taken from a tripod at the 50 yard line. On the target below the center and top right are four shot groups and the rest are five shot groups.
SILENCER SATURDAY #270: On The Range – SIG MCX-SPEAR LT And SLX556-QD
I am a slightly above average shooter using a tripod and standing on icy snow, so I would consider these groups to be fairly decent. The match trigger is smooth with no gritty feeling and a crisp break.
Case ejection was at the 3:30 position when shooting with the suppressor and the the gas setting in the (-) position. In 80 rounds I did not experience a FTF or FTE malfunction of any kind.
The below target has a a 10 shot group.
SILENCER SATURDAY #270: On The Range – SIG MCX-SPEAR LT And SLX556-QD
For utility alone, I’ll probably be swapping to an 11.5″ barrel when they become available. However, the 16″ MCX-SPEAR LT is a smooth, quiet*, and reliable shooter that can perform with the right ammunition. The recoil is minimal and the trigger is plenty good for a semiautomatic fighting carbine. I have been on an MCX kick for the last few weeks and the SPEAR LT is a good reminder of the reasons why I love this platform. It’s not perfect, but it’s close.
Have a great week. Be safe, have fun, and we’ll see you back here next weekend for another Silencer Saturday.
