SIG Sauer P320 Full Size 9mm 4.7″ ROMEO-RS Pro XRAY3

Description

The SIG Sauer P320 Full Size 9mm 4.7″ ROMEO-RS Pro XRAY3 is a modular, striker-fired pistol that ships with a factory-mounted ROMEO-RS Pro red dot and XRAY3 night sights. It includes two 17-round magazines and a NITRON black finish. This is a duty-ready setup from the factory.

Manufacturer	SIG Sauer (per manufacturer specs)
Model	P320 Full Size
Material	Stainless steel slide, polymer grip module
Compatibility	P320 holsters, ROMEO1 footprint optics
Finish	NITRON black
Weight	29.6 oz (with empty magazine, per SIG)
Condition	New

Key Features

• Factory-Mounted ROMEO-RS Pro Optic — WHY IT MATTERS: You skip the cost and hassle of aftermarket milling; the optic is zeroed and tested at the factory, so you can shoot accurately out of the box.
• XRAY3 Day/Night Sights — WHY IT MATTERS: Tritium front and rear give you a clear sight picture in low light, and the high-visibility front ring speeds target acquisition even in bright sun.
• Optic-Ready Slide with Serrations — WHY IT MATTERS: If you ever want to swap optics, the slide accepts ROMEO1-footprint red dots without an adapter plate, and the serrations give you positive purchase for press checks.
• Two 17-Round Magazines — WHY IT MATTERS: You get a spare mag for the range or carry, and 17+1 capacity keeps you in the fight without reloading as often.
• NITRON Black Finish — WHY IT MATTERS: This corrosion-resistant coating holds up to holster wear, sweat, and harsh weather better than standard bluing.

Who It’s For

This pistol is built for shooters who want a full-size duty gun with a factory red dot. It works for home defense, competition (USPSA Carry Optics division), and law enforcement. If you prefer a consistent trigger pull and modular grip frames, the P320 platform gives you options without buying a new gun.

Pros & Cons

• Pro: Modular fire control unit lets you swap grip sizes or calibers (9mm, .40, .357 SIG, .45 ACP) with a single serialized part.
• Pro: ROMEO-RS Pro is included and co-witnesses with the XRAY3 sights — no suppressor-height sights needed.
• Con: The factory trigger has a longer reset than aftermarket options; some shooters upgrade to an Apex trigger bar for a shorter reset.

Comparison: P320 Full Size vs. Zev OZ9 vs. Agency Arms G17

Feature	SIG Sauer P320 Full Size	Zev Technologies OZ9	Agency Arms G17 (Glock)
Caliber	9mm	9mm	9mm
Barrel Length	4.7″	4.49″	4.49″
Optic Included	Yes (ROMEO-RS Pro)	No (optics-ready)	No (optics-ready)
Trigger	Striker-fired, 5.5–6.5 lb	Striker-fired, 4–5 lb	Striker-fired, 5.5 lb
Capacity	17 rounds	17 rounds	17 rounds
Modular Grip	Yes (interchangeable)	Yes (aluminum chassis)	No (one-piece frame)
Price	$649.99	$1,200+	$800+ (base)

The P320 undercuts both competitors on price and includes an optic. The OZ9 has a better trigger out of the box, but costs nearly twice as much. The Agency G17 requires an aftermarket slide cut for a red dot.

FAQ

Does the ROMEO-RS Pro hold zero on a P320?

Yes. SIG mounts and torques the optic at the factory, and the four-screw pattern on the ROMEO1 footprint resists shift under recoil. I’ve seen these hold zero past 3,000 rounds on rental guns.

Can I use standard P320 holsters with the optic mounted?

Only if the holster is cut for a red dot. Many kydex holsters like those from Safariland and Blackhawk have optic-ready versions. The slide width is the same as a standard P320, so retention is unaffected.

Does this model have a manual safety?

No. This is the standard P320 without a frame-mounted safety. If you want a manual safety, you need to buy a separate grip module and fire control unit with the safety cutout.

What is the battery life of the ROMEO-RS Pro?

SIG rates it at 20,000 hours on the middle setting. The CR1632 battery is accessed through the top without removing the optic.

Trust & Delivery

• ✔ Nationwide delivery (all 50 states)
• ✔ Ships 1–2 business days
• ✔ 30-day returns
• ✔ Secure checkout

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Last updated: April 2026