FAXON EXOS-515 PISTOL COMPENSATOR FOR SIG® P320 - 9MM

What the EXOS-515 Does

A pistol compensator threads onto the muzzle and redirects propellant gas as it leaves the bore. Because the bore of a P320 sits above your hand, recoil rotates the muzzle upward — muzzle flip. The EXOS-515 uses that same gas to push the muzzle back down, so the sights settle faster and follow-up shots come sooner. It does not reduce the cartridge’s total recoil energy; it changes the direction the muzzle moves.

EXOS® does this with a single expansion chamber and three ports angled at 45°. Straight-up ports only act on gas after it has left the bore axis; the angled EXOS ports catch it earlier and vector it up and forward, so more of the available energy goes into counteracting flip. A single chamber keeps the comp short and light, which matters on a carry or duty pistol where a long, heavy comp changes how the slide cycles.

The 515 is cut around the P320’s own dimensions. The P320 carries its thread shoulder further from the slide than a Glock® or M&P®, so the rear of the 515 is extended to bridge that distance and mate to the slide nose — which is why the part measures 1.375″ overall even though it adds the same 1.125″ ahead of the slide as every other EXOS®. The bore is sized to the P320 barrel and the guide-rod relief clears the recoil assembly through the full slide stroke.

What’s Included

Tested Performance

Faxon measured the EXOS-515 in a Ransom rest on a SIG® P320 Full-Size, firing 115 gr 9mm and recording the muzzle’s peak upward rotation in degrees with a bare threaded barrel and with the comp installed. Leading aftermarket compensators were run on the same host under the same conditions.

Averages of recorded shots on the P320 Full-Size host. The P320 starts with less muzzle rise than a micro-compact, so the percentage is smaller; the comp still removed more than five degrees of climb. Results vary with ammunition, recoil spring, and grip.

Installation

EXOS-515 FAQs

Which pistols does the EXOS-515 fit?

The SIG® P320 Full-Size in 9mm with a 1/2x28 threaded barrel, which is the platform it was engineered and function-tested on. The P320 Compact and Carry share the slide and barrel diameter and are generally compatible, but were not the test platform, so use on those is at the owner’s discretion. The P365 and P365 XL use the EXOS-525.

How much does it reduce muzzle flip?

In Faxon’s Ransom-rest testing on a P320 Full-Size with 115 gr 9mm, the EXOS-515 reduced peak muzzle rise by 22% versus a bare threaded barrel — from 24.0° to 18.8° — the lowest rise of every compensator tested on that host.

Why is the EXOS-515 longer than the other EXOS® comps?

Because the P320’s thread shoulder sits further from the slide nose than on a Glock® or M&P®. The rear of the 515 is extended to bridge that gap so the comp sits flush against the slide. Ahead of the slide it adds the same 1.125″ as every other EXOS®; the extra length is behind the muzzle, not in front of it.

Will it sit flush with my slide?

On a Faxon P320 threaded barrel, yes. On other 1/2x28 barrels, it sits flush when the muzzle protrudes 0.600″ or less past the slide; with more protrusion it still works but stands off from the slide.

Do I need a different recoil spring?

Usually not with standard-pressure or +P ammunition. A compensator bleeds off gas that would otherwise help drive the slide, so very light target loads can occasionally fail to lock the slide back on the last round. Step up to a standard 115–124 gr load first; a slightly lighter recoil spring is the next option for shooters who run light loads exclusively.

Will my holster still fit?

Installed, the EXOS-515 adds 1.125″ ahead of the slide. Open-bottom holsters generally work as-is; closed-toe holsters need to be cut for a compensator, and most holster makers offer a comp option for the P320.

Does it work with a red dot or suppressor-height sights?

Yes. The single-chamber body keeps a low profile above the bore, so it does not block standard-height sights or a slide-mounted optic. The ports vent upward, so expect some visible gas in the sight picture on bright days, which is normal for any top-ported comp.

Where is the EXOS-515 made?

Machined from 6061 aluminum and black anodized in the USA by Faxon Firearms, a family-owned, federally licensed manufacturer in Greater Cincinnati, Ohio. Covered by the Faxon Lifetime Guarantee.

Faxon Lifetime Guarantee. Covers manufacturing and material defects to the original purchaser. Excludes damage from misuse, neglect, non-standard ammunition, or modifications. Finish wear from normal use is not a defect. Register your product at faxonfirearms.com/product-registration to expedite service. Full terms: faxonfirearms.com/warranty-privacy-terms.

SIG®, P320®, and P365® are registered trademarks of SIG SAUER, Inc. Glock® and M&P® are registered trademarks of their respective owners. Faxon Firearms is not affiliated with or endorsed by any of these companies; trademarks are used for compatibility reference only. EXOS® is a registered trademark of Faxon Firearms. Muzzle-rise figures are from Faxon internal Ransom-rest testing with 115 gr 9mm ammunition; results vary with ammunition, recoil spring, and host condition. Compensators can change a pistol’s operating characteristics; always confirm function with your chosen ammunition before carrying.

For questions, contact customerservice@faxonfirearms.com.