SIG SAUER P320 Full-Size 9mm 4.7″ Nitron (2)10rd
About this product
What is the SIG SAUER P320 Full-Size 9mm 4.7″ Nitron? It's a modular, striker-fired duty pistol engineered for precision range work and reliable home defense, built around SIG's serialized fire control unit for chassis-level customization. Its 4.7-inch barrel length balances sight radius for target shooting with holster compatibility, and the optic-ready slide with Romeo1 Pro footprint accepts popular micro red dots like the Holosun 507C without an adapter plate.
What is the SIG SAUER P320 used for?
The P320 Full-Size serves as a primary platform for high-round-count training, USPSA Carry Optics division competition, and duty-ready home defense. With its 8-inch overall length and 28.3-ounce weight, it soaks up 9mm recoil for faster follow-up shots, while the full-length accessory rail accepts weapon lights up to 1300 lumens like the Streamlight TLR-1HL. Its modular grip system allows hand size adjustment without an FFL transfer, making it a practical choice for households with multiple trained shooters.
How does the P320 compare to the Glock 17 Gen5?
The P320 outperforms the Glock 17 Gen5 in modularity and out-of-box optic readiness, but trails in aftermarket holster compatibility. SIG's chassis system lets you swap grip frames in under 60 seconds without tools, while Glock requires a complete frame replacement. However, the P320's 4.7-inch barrel is 0.2 inches longer than the Glock's 4.48-inch barrel, which provides a marginal ballistic advantage but limits holster options compared to the Glock's near-universal fit.
What does it weigh and what are the dimensions?
The pistol weighs 28.3 ounces loaded with its 10-round magazine and measures 8.0 inches in overall length with a 4.7-inch cold hammer-forged barrel. The slide width is 1.3 inches at its widest point—noticeably broader than a Glock slide—while the medium full-size grip module accommodates hands with a 2.4-inch backstrap-to-trigger reach. Unloaded weight is 29.6 ounces, making it 4.2 ounces heavier than a comparable the Stevens 334 Rifle in .308 Win but balanced for rapid transitions.
Who is this NOT for?
This configuration isn't for concealed carry applicants or shooters prioritizing maximum magazine capacity. The full-size frame prints conspicuously under standard concealment garments, and the 10-round limit reflects compliance-focused distribution rather than performance—competing duty pistols like the FN 509 Tactical ship with 17-round magazines. Budget-conscious buyers seeking a first hunting sidearm would be better served by the value-oriented Stevens 555 Sporting O/U Shotgun line review where every dollar goes toward reliability rather than modularity.
What's in the box?
You receive the complete pistol with two 10-round polymer magazines, SIGLITE front and rear night sights pre-installed, a medium full-size black polymer grip module, and the optic-ready slide assembly. Notably absent is a hard case—SIG ships these in cardboard—and any tools for grip module removal, requiring a 3/32-inch punch or similar implement for disassembly. The package includes one chamber flag and the standard manual, but lacks the cleaning rod and brush included with European imports.
Is the P320 worth it at $517.99?
At $517.99, the P320 Full-Size justifies its price through military-proven reliability and chassis-based future-proofing that cheaper pistols can't match. You're paying approximately $90 over a comparable Glock 17 MOS for SIG's modular system and superior out-of-box night sights, which would cost $120 separately. For shooters planning multiple grip sizes or barrel lengths, this platform saves money long-term compared to buying separate dedicated pistols for competition, training, and defense.
Specs at a glance
Video review
Pros & cons
What works
- Military-proven M17/M18 fire control unit with 30,000-round mean rounds between failure rating
- Optic-ready slide accepts Holosun 507C/508T/509T models directly—no $40 adapter plate required
- Modular grip system swaps sizes in under 60 seconds without tools or FFL paperwork
- SIGLITE night sights provide 15-year tritium illumination with 0.25-inch white ring contrast
Trade-offs
- 10-round magazines limit training efficiency—aftermarket 17-round mags cost $45 each and may not be state-compliant
- Nitron finish shows holster wear faster than Cerakote—expect visible slide wear after 250 draw cycles
- No hard case included—aftermarket Pelican 1170 costs $40 plus custom foam cutting time
- Medium grip texture lacks aggressive stippling—requires $75 grip tape or professional stippling for high-sweat scenarios
Expert review
Key attributes
| upc | 798681699124 |
| manufacturer | SIG SAUER |
| manufacturer part number | 320F-9-BSSP-10 |
| action | Semi-Auto |
| atf type | Pistol |
| barrel length | 4.7'' |
| caliber/gauge | 9mm |
| capacity | 10+1 |
| color | Black |
| length | 8'' |
| magazine included | 1 x 10-Round |
| model | P320 |
| number of magazines | 2 |
| package height | 3.0 |
| package width | 10.0 |
| product type | Striker Fired |
| safety | No |
| shipping weight | 3.4 |
| sights | Siglite Night Sights |
| sights type | Night Sights |
| slide description | Optic Ready/Serrated |
Frequently asked questions
- Is it compatible with Holosun 507C red dots?
- Yes, directly—the optic-ready slide uses SIG's ROMEO1/PRO footprint, which accepts the Holosun 507C, 508T, and 509T models without an adapter plate. You'll need to purchase the appropriate mounting screws separately since SIG ships the pistol with filler plates installed. Total installation time is under 10 minutes with a 1/16-inch hex key and torque driver set to 15 in-lbs.
- Does it fit in a Glock 17 holster?
- No—the P320's slide is 0.15 inches wider and the trigger guard geometry differs significantly, requiring a dedicated P320 holster. Safariland 6378 ALS models for the P320 Full-Size with weapon light accommodate most configurations, while kydex makers like T-Rex Arms offer custom options with a 2-3 week lead time. Always verify holster compatibility includes your specific light model before ordering.
- Can I convert this to a compact frame later?
- Yes, by purchasing a separate P320 Compact grip module and corresponding 15-round magazine—the fire control unit drops directly into any P320 grip size without an FFL transfer. The conversion takes under 2 minutes and costs approximately $45 for the grip module plus $35 per magazine. The 4.7-inch barrel will protrude 0.8 inches beyond a compact frame, creating a 'carry-comp' configuration common in competition setups.
- How long does shipping take to California?
- Legally compliant shipments to California require 10-day waiting periods after the dealer receives the pistol, followed by 2-5 business days for priority shipping. Ironclad Armory processes all 4473 paperwork within 24 hours of receiving your local FFL's information. Total timeline from order to pickup typically spans 12-18 calendar days depending on your receiving dealer's volume.
- Does this work with a SilencerCo Octane 9 suppressor?
- Yes, with a compatible threaded barrel—the factory 4.7-inch barrel is not threaded, requiring an aftermarket replacement from SIG, SilencerCo, or Bar-Sto. SilencerCo's P320 threaded barrels feature 1/2x28 threads and cost $180-$220, adding 0.6 inches to overall length. Always verify suppressor alignment with a 0.358-inch alignment rod before firing to avoid catastrophic baffle strikes.