Description
The Sig Sauer P320 MOD Full Size is a factory-built competition-leaning P320: a ported slide that vents gas upward to flatten muzzle rise, a ROMEO-X reflex sight supplied with the gun, the X-Series flat trigger, and three 21-round magazines in the box. It is the configuration people used to assemble themselves from parts, sold as one package. Part 320XF-9-MODRX-SL, UPC 798681740260.
What the Porting Does
A ported compensating slide cuts openings through the top of the slide and barrel so a portion of the propellant gas escapes upward as the bullet passes. That upward jet pushes the muzzle down, countering the rise that recoil would otherwise produce. On a 9mm the effect is subtle in absolute terms and obvious on a timer: the dot settles faster, so the second shot comes sooner.
It is not free. Porting bleeds gas that would otherwise drive the bullet, so velocity drops slightly, and the vented gas carries unburnt powder that fouls the top of the slide and the underside of an optic. Shooting a Sig Sauer P320 MOD Full Size at night also produces noticeably more visible flash directly in front of your sight picture than an unported gun.
The Sig Sauer P320 MOD Full Size slide is matte black DLC, which is a harder and slicker coating than standard Nitron and resists the abrasion that porting residue causes. It is serrated front and rear and cut for the optic that ships with it.
The Optic, the Trigger and the Frame
A ROMEO-X reflex sight comes with the Sig Sauer P320 MOD Full Size rather than as a separate purchase, which is most of why the package makes sense at this price. Buying a comped slide and a quality enclosed-emitter dot separately costs more than the difference between this and a base P320.
The X-Series flat trigger is the other upgrade worth paying for. A flat face gives a consistent finger contact point and makes the break feel lighter and more predictable than the curved shoe on a standard P320. Combined with the ported slide, the Sig Sauer P320 MOD Full Size is set up for speed rather than for carry.
Underneath, the Sig Sauer P320 MOD Full Size is still a P320. The serialized component is the fire control unit, a small stainless chassis that lifts out of the full-size X-Series polymer grip module, so the grip is a part rather than a firearm. Overall length is 8.3 inches, there is a Picatinny rail for a light, and three 21-round steel magazines ship in the box.
- Part: 320XF-9-MODRX-SL, UPC 798681740260
- Caliber: 9mm Luger
- Barrel: 3.9 in.
- Overall length: 8.3 in.
- Action: striker-fired, modular fire control unit
- Slide: matte black DLC stainless, ported and serrated, optic cut
- Trigger: X-Series flat trigger
- Grip module: full-size X-Series polymer with Picatinny rail
- Optic: ROMEO-X reflex sight supplied
- Capacity: 21+1, three 21-round steel magazines included
Honest Caveats Before You Buy
Porting is a trade, not a free upgrade. You gain a flatter-tracking pistol and you accept more muzzle flash, more fouling around the optic and a small velocity loss. If this gun is going to sit on a nightstand and be fired indoors in the dark, an unported P320 is the better choice. If it is going to a match or a range with a shot timer, the Sig Sauer P320 MOD Full Size earns its keep.
Maintenance on a Sig Sauer P320 MOD Full Size goes up. Vented ports deposit carbon on top of the slide and on the underside of the optic lens, and a dirty lens degrades a dot faster than most shooters expect. Plan on wiping the glass and the port area every range session rather than every few.
The Sig Sauer P320 MOD Full Size is not a carry gun. Eight point three inches long with a ported slide and a full-size grip is a range and competition pistol. It will conceal under a coat and nowhere else, and the porting sits right where a holster mouth would otherwise protect it.
Who it suits: competition shooters who want a comped, dot-equipped pistol without assembling one, P320 owners who want a dedicated range gun on the same manual of arms as their carry gun, and anyone who values a factory package over a parts project. The Sig Sauer P320 MOD Full Size is a specialist build sold at a sensible price. MAG5 Firearms is a family-owned FFL in Collegeville, Pennsylvania, with transfers, cleaning and gunsmithing in-house by appointment.
Browse more handguns in stock at MAG5 Firearms, or read about the platform on the SIG SAUER P320 page before you order.
Reviews
There are no reviews yet.