Customizing the Already Custom SIG P320 Spectre Comp

By Todd Burgreen –

Back in 2010, I wrote an article about the SIG P250 calling it a benchmark in handgun development. This statement has been validated with the undeniable success of its later-released sibling, the P320. What did the P250 bring forth that the P320 perfected? The heart of the SIG P250, and now the P320, is the removable FCU — Fire Control Unit. The FCU itself is considered a firearm and bears the required serial number marking. The FCU allowed for SIG’s first steps into pistol modularity and, subsequently brought us its P320 successors.

The FCU contains the trigger mechanism, slide catches, slide rails, etc. A SIG P250/320 slide assembly does not interact with the grip module but is guided/operates along the FCU’s integral steel rails located on both sides of the FCUs front and rear. The P250 offered across-the-board modularity in terms of grip sizes, frame and slide interchangeability, multiple trigger positions, and even caliber swapping that heralded the next wave of high-capacity polymer framed handguns. Gun culture members are, by nature, conservative and view new offerings skeptically until proven by use. The SIG P250 found a somewhat cool reception on the U.S. market. The SIG P250’s adaptability to individual shooter needs seemed too good to be true. The hammer-fired P250 became a steppingstone to the striker fired P320 — the rest is history, as they say.

Exeter, NH has evolved into the epicenter of the handgun universe. This is in large part to the polymer striker fired SIG Sauer P320 series that arrived in 2014. Its selection as the U.S. Army’s handgun, and soon thereafter the rest of the DOD, provided vindication for the FCU concept that started with the P250.

SIG’s P320 Spectre Comp

SIG is renowned for introducing new variants of already successful weapons. This is done by combining and adding features based on assessments from competition, tactical, law enforcement, and personal defense customers. You don’t need to reinvent the wheel to have a successful new model. There are currently 21 P320 variants listed on the SIG website. The SIG P320 Spectre Comp is one of the newest P320’s and the focus of this article — with a twist, thanks to FCU-inspired modularity.

The P320 Spectre Comp comes from the SIG Custom Works division. SIG Custom Works offerings are always distinctive in appearance while offering performance enhancing features. The P320 Spectre Comp is the epitome of a Custom Works project. For example, this pistol features a laser stippled tungsten infused grip (TXG) module, titanium nitride (TiN) gold-colored barrel and trigger, and a Custom Works milled slide. The Spectre Comp comes standard with XRay3 day/night sights, a flat XSeries trigger, and is optic ready out of the box. It’s further distinguished with a factory installed compensator.

The combination of the Spectre Comp’s full-sized TXG frame with single port compensator makes this pistol one of the smoothest-shooting 9mm handguns on the market. The tungsten infused frame not only adds weight but concentrates it in your hand, thus lowering the pistols center of gravity for better controllability. It’s smooth in its slide cycle and is noticeably easier to track its sights during recoil than other pistols in the same caliber. This is thanks to the compensator doing its job and its iron sight arrangement. All of this translates into a handgun that stacks rounds on top of each other in a hurry. Unabashedly, the P320 Spectre Comp is one of the sweetest shooting handguns I have experienced over 25+ years of evaluating weapons.

A 41-ounce handgun is stout to carry, though, to the say the least. Gravity never rests. So, we asked ourselves how to decrease weight while maintaining the gun’s smooth shooting characteristics, and we found SIG’s inbuilt modularity was the path forward.

Enter SIG’s Aluminum AXG Grip Module

While the Spectre Comp features SIG’s TXG grip module, we wanted to reduce the pistol’s weight and chose to mate it’s FCU with SIG’s aluminum AXG grip module. This grip module features Hogue G10 grip panels and a rear insert. The P320 AXG metal lower offers a distinctive ergonomic feel that will appeal to many. What could be better than a proven, striker-fired handgun exuding the classic feel of metal in your palm? Not much. The AXG’s generous undercut, extended beavertail, and four-sided beveled magazine immediately sends positive signals to the right side of your brain.

Swapping Grip Modules

The FCU from the Spectre Comp was easy to transfer over to the AXG frame without tools. It’s a simple swap… with the slide locked to the rear, rotate the takedown lever, release the slide and slip it off the frame. The takedown lever is removed from the frame by rotating it further around and pulling it out simultaneously. This frees the FCU for removal. Rock it upward while drawing the trigger shoe backward and slip it up and out. It installs in the AXG grip module by following the steps in reverse order. Swapping the TXG grip module out for the AXG shaved a half pound from the original P320 Spectre Comp configuration. Our AXG Spectre Comp pistol weighs in at 32 ounces. This represents a weight reduction of about 20% compared to the stock gun. Slightly more weight could be shaved off if a polymer SIG grip module was chosen versus the AXG module.

The Compensator

With the P320 Spectre Comp slide mated to the AXG frame, it was time to explore what our P320 AXG Spectre Comp handgun offered. The SIG compensator is screwed on the Spectre’s threaded barrel and then further secured with two screws. The tapered screws are installed from the top of the comp, interacting with notches milled into the side of the P320 Spectre barrel to ensure proper timing of the comp. This is especially important considering SIG has placed the front sight on the comp. This maintains maximum sight radius and allows for superior front sight tracking between shots since the front sight does not reciprocate with the slide. A sharp eye will see that the SIG comp’s port is angled slightly forward to better direct gasses and lessen muzzle flip/rise.

The P320 Spectre’s slide to compensator interaction is not your typical screw on comp arrangement. SIG Custom Works has milled an O-ring-like projection into the front of the slide that interfaces with a similar sized cavity in the compensator for a tight fit between slide and comp. The AXG frame does place the compensator fully in front of the frame’s dust cover, whereas the original SIG set up with the Spectre Comp protrudes only 1/8 inch past the dust cover due to the larger TXG grip module.

While the SIG XRay3 day/night sights are excellent factory sights, the ability to mount a red dot sight could not be resisted. A SIG ROMEO1 Pro mated up to the P320 Spectre Comp slide. With the red dot installed, range testing commenced with the P320 AXG Spectre Comp. The SIG compensator design produces extremely light recoil impulse and muzzle flip due to the single chamber comp using muzzle gases to drive the slide down versus tilting upward compared to a non-compensated weapon. This is key in keeping the handgun on target.

Just as with red dot sights on handguns, compensators are expanding beyond competition applications and becoming more prominent on personal defense weapons. Why? Part of the challenge of using a handgun involves controlling muzzle flip. No one is saying a 9mm needs a brake. Do not confuse a muzzle brake with a compensator. However, controlling muzzle rise is a valid goal.

Similar to red dots, compensators will be in the running for similar acceptance on personal defense weapons. This is thanks to specific designs such as those found on the Spectre Comp where compensator is efficient. It’s also worth noting that comp is shaped to allow typical holster use. For example, the streamlined nature of the SIG compensator allows it to fit into open-bottomed P320 holsters.

On the Range

Magazines were loaded with SIG Sauer, Ammo Inc., Federal, Hornady, Remington and Black Hills ammunition. Our AXG Spectre Comp combo was fired one handed, including use of the non-dominant hand, to verify there was no sensitivity in terms of reliability with the compensator. The pistol showed it could digest anything fed to it. Premium self-defense JHP, target, and match 9mm loads including 115-, 124-, and 147-grain bullets were shot. The AXG Spectre Comp performed without fail.

The big question with the SIG P320 Spectre Comp combined with the AXG module was making sure performance was not compromised. The ROMEO1 Pro stayed on target, floating briefly out of the IPSC target’s A zone, but never went totally off target… even during multiple round drills. The P320’s simplicity of operation, consistent trigger pull, and compensator allowed for rapid engagement of targets. This is further accentuated with well laid out ergonomics ensuring that the hand is near optimum grip position as soon as the P320 AXG Spectre combo clears the holster.

Performance

A Note About Magazines

The P320 Spectre Comp’s original flared magazine well necessitates either SIG Legion magazines with Henning Group baseplates or 21-round P320 magazines. Standard P320 magazines with front-radiused baseplates require modification to fully seat in the SIG TXG grip module’s flared magazine well, or the magwell needs removed to work with the standard 17-round P320 magazines. The AXG frame is not particular over P320 magazine type used.

Conclusion

Our P320 AXG Spectre Comp will be recognized as an amalgamation of positive features found on its striker-fired predecessors as well as many innovative tweaks. Many may ask what this pistol offers to shooters compared to other striker-fired handguns already on the market. Red dot compatibility and compensator are certainly nice touches. The ability to tweak the P320 Spectre Comp with a AXG grip module without impacting performance highlights the versatility of the SIG modular design. Based on SIG’s track record, we’d not be shocked to see a variety of compensated P320’s emerging soon. The P320 XTen is an obvious candidate for a comp treatment.

Specifications

Make: SIG Sauer
Model: N/A
Caliber: 9mm Luger
Barrel Length: 4.6 in
Overall Length: 8.5 in
Sights: X-RAY3 Day/Night Sights (SIG ROMEO1 PRO mounted)
Sight Radius: 6.5 in
Height: 5.8in
Width: 1.6in
Weight Empty: 32oz
MSRP: SIG P320 Spectre Comp $1400; SIG AXG Grip Module $299; SIG ROMEO1 Pro $350
URL: sigsauer.com