Other manufacturers often forget about their civilian customers after getting a taste of military contracts. However, SIG’s dynamic leadership team keeps the hammer down, either offering new items or improving existing weapons based on feedback from its customers. Even with its preeminent position, SIG has no problem teaming up with other firms to create unique, enhanced versions of existing SIG products. The SIG P320-FLUX LEGION (FLUX LEGION) braced pistol is an excellent example of this.

Sig Sauer P320-FLUX LEGION PDW

Many consider SIG P320 the new standard for fighting pistols based on capacity, weight/firepower ratio, ruggedness, and reliability. The SIG SAUER and FLUX Defense collaboration—the FLUX LEGION—seeks to capitalize on these positive traits. It combines a FLUX Defense braced chassis and P320 FCU, LEGION skeletonized trigger, and integrated compensated LEGION slide.

The FLUX LEGION transforms the P320 handgun into a viable personal defense weapon (PDW) category. It is a complete SIG factory build, not something you assemble via separate FLUX chassis and SIG components.

The polymer striker-fired SIG P320, which arrived on the scene in 2014, has evolved into an industry leader for duty and personal defense handguns. Its selection as the US Army’s new sidearm in January 2017 via the MHS (Modular Handgun System) Competition solidified this position. Soon after, all other US branches of service adopted the P320 in its M17 or M18 form.

The heart of all SIG P320s is the fire control unit (FCU). The FCU is considered the pistol and bears the required serial number marking. It fits into a grip module or, in this case, the FLUX Raider chassis.

The LEGION slide does not interact with the FLUX chassis but is guided/operates along the FCU’s integral steel rails located on both sides of the unit front and rear.

FLUX Defense Chassis

The FLUX Defense chassis has a Legion Gray finish and a rapid-deploying stabilizing brace. It also features an ambidextrous dual-magazine release system, a front Picatinny mount, a rear non-reciprocating Picatinny optic mount, and an integrated flared magazine well.

Additionally, it boasts an ambidextrous safety—that’s right, a functioning safety. So important, considering how the FLUX LEGION may be dangling off a sling around your shoulders.

The FLUX LEGION ships fully assembled with two 30-round P320 magazines. A SIG ROMEO5 GENII perched on top of the non-reciprocating Picatinny rail finishes off the package.

Slide-mounted SIG XRay3 Day/night iron sights are still usable/visible thanks to the portal found in the rear of the FLUX chassis under the optic mount.

FLUX Flex for Personal Defense

The FLUX LEGION was designed with personal security details and covert operations in mind. However, I offer it has a viable role in your personal defense arsenal. Comparing it to a micro-SMG is an easy leap with the FLUX LEGION, considering 9MM chambering and 30-round magazine usage.

For me, the FLUX LEGION is more comparable to a machine pistol than SMG since it can be fired similarly to a normal handgun if needed. I don’t know why you would, considering the advantage of a brace, but it is still easily done.

Many pontificators have been claiming the end of the submachine gun (SMG) as a viable weapon class. They point to the SMG’s steady relegation to the sidelines in terms of use since the end of WWII.

The first impetus along this path occurred with the rise of the assault rifle. It was characterized by controllable select fire capability with its intermediary round compared to the full-powered main battle rifles of the early 20th Century.

The appearance of personal defense weapons (PDWs) stimulated by multiple NATO weapon requests seemed to sound the final death knell of the SMG. The PDW is characterized by its compact size. However, it is centered around new cartridge designs that facilitate body armor penetration out to a couple of hundred yards.

9mm for CQB

While certainly not comparable to a rifle cartridge, a 115-147gr 9MM (.355 diameter) instills more confidence than a 23gr .22 caliber (or less) when putting down an opponent in close quarters.

The SMG’s most prominent role, indeed its raison d’être stretching back to the WWI trenches, is as a CQB weapon. Indeed, the rise of the assault rifle after WWII slowed the expansion of SMGs related to overall armed force adoption, with SMGs confined to specialized units.

However, the increase in terrorism, organized crime, and drug smuggling, with the resultant militarization of law enforcement (LE) teams to deal with these well-armed opponents, found a new home for the SMG. I offer all of this also points to a role for the SIG FLUX LEGION involving civilian needs.

It is pretty damn handy to have a 30-round magazine in the grip. Another 30-round magazine is held under the front of the trigger guard, and a quick dual magazine release feature is available.

SIG P320 17-round and 21-round magazines are also available for use. Easy to mount—and reach—tactical light on the front Picatinny rail section is another bonus of the FLUX LEGION.

Picking the Right Tool for the Job

Many will question employing a pistol cartridge in a brace-fired weapon with the plethora of assault rifle models available. Others would argue that most engagements happen well within a 50-yard range, especially in LE, MOUT, or civilian settings. This adds the caveat that handling and reliability are more factors in quick, reactive engagements than the specific caliber used.

A civilian concerned with home defense will find no compromise with SIG FLUX LEGION. It offers a high capacity, great handling, and extended range/accuracy compared to traditional a handgun.

Will a rifle hit with more authority than a 9MM? Yes, of course. But mission specifics may dictate when the FLUX LEGION is a more practical choice of weaponry.

The muzzle blast differential between a 9MM and an obnoxious rifle muzzle signature is further accentuated in confined spaces. This is especially true inside a home in a personal defense role.

Origin Shooting Outlaw Steel Proving Ground

After a few range visits, I became familiar with the FLUX LEGION by sighting in and running various drills. So, I decided to take advantage of an upcoming Origin Shooting Outlaw Steel Match. I entered the PCC category with the FLUX DEFENSE instead of my normal Open division.

Yes, I may have been rash for my first go at PCC with a weapon I was not yet totally dialed into. However, the opportunity was too good to pass up. Plus, the FLUX LEGION just makes you believe in it.

Origin Shooting’s founder is Ken Bloxton. Ken’s introduction into the shooting culture started after 9/11. He was a senior in high school, joining the Army soon after graduation.

Following the Army, his competitive shooting career began. He was the 2015 Two-Gun Nationals Champion and placed 5th in the Three-Gun Nationals same year.

He created Origin Shooting in 2017 with an emphasis on enhancing students’ speed, placing rounds on target accurately, even when combined with movement. After all, this would facilitate better performance no matter the situation.

Competing is encouraged by Origin Shooting to better define weaknesses, thus allowing weaknesses to be overcome.

Running the P320-FLUX LEGION

The on board dual magazine configuration, along with integrated compensated LEGION slide, serves to balance the FLUX LEGION and minimize recoil or muzzle climb. Accurate strings of fire consisting of multiple rounds presented no problems. It was easy to keep rounds smacking steel due to minimal muzzle climb and muzzle blast.

The stationary ROMEO5 GEN II red dot provided an advantage in acquiring the next target versus a red dot mounted on a handgun slide. Even though chambered in 9MM, the FLUX LEGION is a much more potent package than any similarly chambered handgun. This is due to its increased accuracy—therefore, effective range—all with a boost in ammunition capacity.

Likewise, the deployed brace with hands spread further apart offers far more stability than when handling a handgun. This is based on multiple points of contact when interfaced with the shooter.

The Origin Shooting match stages offered an opportunity to work on transitioning across multiple targets, moving to different shooting boxes, and reloading.

The dual magazine release is pretty slick! You still have the capability to drop only the magazine in the grip. However, when it’s time to grab the fresh onboard magazine in the front frame storage pocket, hit the dual release button and the magazine in grip drops out along with the front one.

Make sure you have a grip on the front one or you will muck up your reload as both magazines will hit the deck. Ask me how I know.

A Failure-Free Performance

Without equivocation, no failures were experienced, no matter how quickly or how many 30-round SIG “happy sticks” were fired. This is a credit to both SIG and the FLUX Defense chassis being well designed. So, it did not interfere with the weapon’s functioning.

A large portion of the SIG LEGION slide and ejection port is not obscured, further preventing reliability issues. The SIG slide lock lever is readily accessible if you send your slide forward via a slide lock reload.

If you are a “slingshotter” get used to using the front of the slide as access to the rear will be impeded by chassis. SIG has provided deep serrations on the LEGION’s slide to assist.

The practice of using a glove on your offhand is encouraged. The slide gets hot after sending a couple dozen rounds downrange quickly over multiple stages of fire. Ask me how I know.

Recap

The SIG FLUX LEGION is an interesting introduction to the market that will spark debate about its viability. However, the FLUX LEGION holds its own. Its brace is quick to deploy, and sturdy once opened in the shooting position.

The old standard of having a carbine and handgun chambered in the same caliber should not be casually dismissed. Many would favor discrete off-body carry of the FLUX DEFENSE in a backpack or briefcase with another SIG P320 handgun carried concealed. This would offer the advantage of same caliber/magazine interchangeability.

What could be better than not only using the same cartridge but also the same magazines? The availability of proven SIG 30-round 9mm magazines is a huge advantage for the FLUX LEGION platform.

For many, the SIG FLUX DEFENSE portability to effective firepower ratio will trump a rifle’s power. It enhances the SIG P320 handgun into a PDW with enhanced effective range via brace stability and red dot options.

The SIG FLUX DEFENSE does not compromise in handling or reliability. A user has just as positive a feel with it as one would with a dedicated PDW or SMG. Few other weapon systems match the options in size, reliability, and capability of the SIG FLUX DEFENSE—especially for the civilian consumer.

For more information, please visit SigSauer.com.