The current theme of special operations weapons seems to be small and quiet. I can’t blame them. Small, lightweight weapons with suppressors are quite comfortable for a wide variety of roles. When you have a far-from-average job, you need far-from-average equipment. That’s where guns like Sig Sauer’s LVAW come into play. LVAW stands for Low Visibility Assault Weapon, and it’s become well-represented in the hands of the men of the Army’s elite Delta Force, the Navy’s famed SEAL teams, and other JSOC commandos.
The LVAW offers selective fire capability and is only available to police and military forces. From the military perspective, this rifle is a submachine gun (SMG) killer. For the longest time, suppressed 9mm SMG platforms dominated the quiet-riot role. Capable as these weapons can be, however, they’re limited by the ammunitions. The 9mm round offers pretty poor penetration when compared to most standard rifle calibers. Weapons like the SIG LVAW were designed to provide an extremely quiet and compact weapon that brings rifle cartridges to the table, making them a superior alternative to an SMG is just about every way.
At Its Core
At its core, the SIG LVAW is a SIG MCX rifle designed and modified to fit a specific mission type. The MCX rifle from SIG Sauer is a short-stroke piston gas-operated rifle series. While the classic Stoner design has been proven to work extremely well, they tend to lose reliability when barrel length is limited to under 10.3 inches.
Short stroke gas piston guns work extremely well with short barrels, and the LVAW has one of the shortest rifle barrels on the market. It features a 6.75-inch barrel, which, I should point out, is absurdly short for a rifle. The SIG MCX design uses an upper and lower receiver that mimic the famed AR 15 and M16 series of rifles. This ensures the controls of the LVAW perfectly match the service rifles operators grow up on in service. This lowers the training time required to get familiar and proficient with the weapon and allows for a retained standard manual of arms across platforms.
Since the gun uses a short-stroke gas piston, there’s no need for a buffer, buffer spring, or buffer tube. In order to make things even more compact, SIG installed a simple folding stock that allows the gun to maintain even lower visibility when stored or stashed.
SIG also equipped the weapon with a modular handguard and industry-standard optics rail. Commandos can attach optics of all kinds, as well as PEQ-15s, lights, and whatever else they may need to make the LVAW better suited to its environment. It’s a short and lightweight weapon; however, tracking down official measurements has proven difficult.
Into the LVAW
The super-short barrel seems odd for a rifle, but keep in mind the LVAW was designed from the outset to be used with a suppressor. In fact, without a suppressor, you could actually damage the rifle’s handguard. The handguard encompasses the barrel and a portion of the suppressor. Without the suppressor, the muzzle blast can damage the handguard. While the suppressor likely can be removed, it seems feasible that it might be only for maintenance purposes.
The suppressors obviously reduce the signature of the gun while fired (though certainly not to the extent depicted in movies). It also acts as a means to lengthen the barrel and increase the velocity of the round, which is important due to the super short 6.75-inch barrel.
In terms of sound reduction, the SIG suppressor brings the sound of the LVAW down to a level that almost matches the MP5SD. The MP5SD is a 9mm suppressed submachine gun that’s widely considered one of the quietest options available for its purpose, which put the LVAW in good company. The suppressor also eliminates muzzle flash and helps control muzzle rise and recoil; making the user harder to spot during an engagement and making it easier to put their second and third rounds on target respectively.
All this makes the LVAW an extremely capable Close Quarters Battle (CQB) weapon. You’re not slapping it in a Caldwell Lead Sled and measuring groups. Its quiet operations allows the operator to engage threats without causing an alert. But lowering the volume does more than that. When the gun is used inside a vehicle or in extremely close quarters with teammates, operators can still communicate with each other and avoid causing serious hearing loss, as is prone to happen when using un-suppressed weapons in tight situations.
It’s hard to overstate just how loud gunfire can be in an enclosed space. The noise can permanently damage the hearing or those nearby and significantly reduces an operator’s situational awareness. But the LVAW design doesn’t do it all by itself. It functions so silently due, in part, to its round of choice: the 300 Blackout.
Into the 300 Blackout
The 300 Blackout cartridge is relatively young when compared to most of its military peers. This cartridge was developed for a very specific purpose, and that purpose includes exactly what the LVAW does. The 300 Blackout was designed to functioned extremely well when fired from a rifle with a short barrel.
On top of that, or maybe as a part of that function, the 300 Blackout was also designed to function well with suppressors. It can utilize both supersonic and subsonic rounds without needing any internal parts swapped out. Subsonic rounds, for those who aren’t ammunition savvy, don’t break the sound barrier, eliminating the supersonic crack that makes up a fair portion of the audible bang when the weapon is fired. Using subsonic rounds in a suppressed weapon makes for a very quiet day.
The downside to subsonic ammo is that it’s really only useful at short ranges. So LVAW users can use subsonic ammunition when they need to remain sneaky and quiet, and then swap magazines for supersonic rounds when they need to extend their range on the fly.
As a rifle cartridge, the 300 Blackout provides better penetration and range than any pistol round. It beats soft armor and deals more damage to hard armor. It’s extremely effective, and the 300 Blackout makes the LVAW one highly versatile firearm.
The Low Visibility Assault Weapon
SIG’s LVAW strikes a certain chord with the special operations community, and it comes as little surprise that it’s been seen in the hands of DEVGRU (colloquially known as SEAL Team 6) and Delta commandos. Specifically, it seems to be a very popular weapon for personal security details. General Austin Miller’s bodyguards were seen carrying these firearms in Afghanistan, and it’s easy to see why. They’re small but capable and work well, both in and out of buildings and vehicles.
The LVAW likely won’t ever be a general issue service rifle; it just wasn’t designed to be. However, in its niche, it’s tough to find a better option. It’s a low-issue item used for specific mission sets, and a fascinating design that seems to be popular among the elite of the elite.
This platform locks up targets with one, much more efficient than the 77gr 5.56, which proved damn impressive itself upon its initial arrival. The ballistic conversation is not conducive with reality, without being aware of the specific round utilized. It’s just that different and the terminal effect it introduces, inherently has a major impact on the discussion. This weapon system is not being criticized or judged by a ballistic expert committee, nor was it…..it was evaluated by its’s operational effectiveness through opportunistic implementation of use . The outcome was indisputable and continuing examples of its devastating impact are ongoing.
300wm surgeon says
Everybody’s an operator/ ballistics Jedi these days huh, the 300bo was developed and purpose orientated for cqb, and surgical threat elimination, and the 6.8 doc was developed for completely different scenarios, the argue which is better is like arguing over a hammer and a fillet knife , the Sig MCX was chosen by operators to be a certain type of tool and they seem to be happy with it.
Bob White says
“Since the gun uses a short-stroke gas piston, there’s no need for a buffer, buffer spring, or buffer tube.”
False. The buffer/spring assembly is totally independent of the operation by the piston. There are short-stroke (and long stroke) systems that still require a buffer, and conceivably a DI system could be made bufferless.
Somebody buy these operators an Arisaka finger stop for their SBR’s (or LVAW’s. I know new acronyms sell but c’mon man enough). And the .300 Blackout is a great round at short range and made for subsonic, so that’s fine, but at distance (even with the faster loads) it’s poor. A 6.8 mix is a much better mix. The 6.8 subsonic load delivers only slightly less energy as it’s bullet weighs less. But if the operator must engage at distance, the 6.8 rules all over the place. More terminal ballistics, flatter trajectory meaning less adjustment on target, more penetration and more accurate.
I’m sure the people at Tier 1 are evaluating every tool for the tasks they have.
Thomas Acton says
someone doesn’t know the ballistics of 110-125 grain 300 rounds out of short barrels.
The 6.8 case is larger & can hold more powder. Given the same weight bullet, 110 Grain, the 6.8 bullet will have a better ballistic coefficient. More powder is faster, better BC is flatter trajectory and more accurate.
There’s no viable measure where the 300 Blackout will be better at anything “at distance.”
First, the primary mission of this weapons is CQB, not long range. You can’t, at this point in time, optimize for both CQB and long range. You won’t “rule all over the place” using a .277/6.8 with a short 6.75″ barrel and lighter bullet with lower BC. You optimize for the primary mission and the .300 BLK is superior in almost every way for CQB, subsonic.
Ballistic Coefficient is weight, diameter and form of the projectile. BC of a Nosler 220 gr .308 is 690, a 6.8 (.277) 165 gr has a BC of .620. BC favors the 300 BLK. More powder or speed doesn’t change the BC.
More powder also doesn’t matter, which powder and then amount does. Using Nosler reloading data for example, a 300 BLK with a 220 gr bullet & 9.5 gr of 2400 will be supersonic @ 1213 fps while 11.0 gr of 4198 with the same bullet will be subsonic at 1100 fps. Less powder, faster bullet. Which powder matters. Additionally, when loading subsonic rounds, you aren’t filling the case with powder. You may be about 50%. The larger case of a 6.8 is not an advantage, and may be disadvantage.
Let’s be clear about ballistics. Internal Ballistics is what happens inside the cartridge & barrel. External Ballistics is what happens from the moment the projectile leaves the barrel and before it hits the intended target. Terminal ballistics is what happens when the bullet hits it’s target.
If you are shooting subsonic, you are speed limited to about 1120 fps, temperature dependent. What matters in this case is Terminal Ballistics and again, the primary mission is CQB & the .308 is superior in this situation. Nosler has a 220 gr HPBT in .308. The heaviest 6.8 I can find is 168 gr. Kinetic Energy is 591 verses 451 pounds feet. The much heavier 220 gr bullet has far more energy at close range than the 168 gr .277. The 300 BLK is far better for defeating body armor or certain types of cover in CQB with such an energy advantage. There is NO speed advantage for the 6.8 in the primary mission.
The smaller case of the 300 BLK favors the round when shooting subsonic. Neither case is filled with powder, typically only about 50%, leaving a lot of empty space.
Long range in a short barrel? The .308 wins again. You can’t accelerate the smaller, lighter bullet enough to gain the speed advantage in a short 6.5″ barrel. The heavier .308 bullets will perform better by retaining more energy at any reasonable range for a short barrel. How far do you think you will be accurately & effectively shooting anything with a 6.75″ barrel? It’s certainly not a 300 meter weapon. The .277 is a great bullet, but it isn’t magic and like every bullet and every weapon, doesn’t excel at everything. Everything is a trade-off.
Dan Glover says
Extremely cogent response Kona.
There is no weapon that does everything.
There is no bullet, weighing any amount, that will be perfect for everything.
There is no weapon system that is universal.
The best any of us can do is to analyze the likely environment wherein we anticipate engaging the enemy. Then endeavor to determine the most likely secondary scenarios, and bring along whatever you can.
Experience taught us all that no plan survives first contact.
Plan to be alive at the end of the day, and adjust for tomorrow in light of what you learned today.
Dan Glover, thank you for saying in fewer words what took me many. Respect.
I love it when facts show up.
The round we ran was manufactured by Discreet Ballistics. Hopefully you can gain some insight into the differences of purposeful application, that was/is considered in the use of this platform. I assure you that the effects are unmatched.