FN 509 Midsize Tactical 9mm, 4.5 in Threaded Barrel FDE
About this product
What is the FN 509 Midsize Tactical 9mm? The FN 509 Midsize Tactical is a purpose-built 9mm pistol with a 4.5-inch threaded barrel, suppressor-height night sights, and an optics-ready slide designed for shooters who need suppressor and red dot compatibility in a balanced-duty platform. This configuration represents FN's answer to the growing demand for compact suppressor hosts that don't sacrifice sight radius or magazine capacity. The Flat Dark Earth finish and fully ambidextrous controls make it equally suitable for duty carry, home defense, or range training scenarios.
What is the FN 509 Midsize Tactical used for?
This pistol serves as a multi-role platform optimized for suppressed shooting and optic-equipped defensive use. The 4.5-inch threaded barrel provides ideal dwell time for suppressor gas management, while the 5.8-inch sight radius ensures rapid target acquisition. With suppressor-height night sights and optics mounting system pre-installed, it's ready for immediate configuration without gunsmithing.
How does the FN 509 Midsize Tactical compare to the Glock 19X?
The FN 509 Midsize Tactical offers superior suppressor compatibility and optic mounting compared to the Glock 19X. While both pistols share similar overall dimensions (7.9 inches versus 7.44 inches), the FN's factory-threaded barrel, suppressor-height sights, and integrated optic system make it approximately $150 more suppressor-ready out of the box. The Glock maintains an edge in aftermarket support and magazine commonality.
What does it weigh and what are the dimensions?
The pistol weighs 27.9 ounces unloaded and measures 7.9 inches in overall length with a 5.8-inch sight radius. The 4.5-inch cold hammer-forged barrel features 1/2x28 threading, while the slide width measures 1.3 inches for comfortable holster compatibility. These dimensions balance concealability with full-size performance.
Who is this NOT for?
The FN 509 Midsize Tactical isn't ideal for budget-conscious shooters or those who prefer traditional iron-sight-only configurations. At $929, it commands a premium over basic duty pistols like the Stevens 334 Rifle, and the suppressor-height sights may print noticeably in concealed carry applications. Shooters who don't plan to run optics or suppressors would be better served by the standard FN 509 model.
What's in the box?
The factory package includes one 15-round magazine and one 24-round extended magazine, with compliance versions shipping with two 10-round magazines instead. Documentation includes FN's warranty information and basic operation manual, but notably excludes thread protectors or optic mounting plates that must be purchased separately. Total unloaded weight with both magazines is approximately 32 ounces.
Is the FN 509 Midsize Tactical worth it at $929?
At $929, this pistol delivers genuine value for shooters needing immediate suppressor and optic compatibility without aftermarket modification. When you factor in the cost of threading a barrel ($150-200), installing suppressor-height sights ($100-150), and milling a slide for optics ($200-300), the FN 509 Midsize Tactical represents approximately $200-300 in saved gunsmithing costs. For serious shooters building a suppressed home defense or duty system, this is one of the most cost-effective routes to a fully configured platform.
Specs at a glance
Video review
Pros & cons
What works
- Factory-threaded 4.5-inch barrel - saves $150-200 in gunsmithing costs
- Suppressor-height night sights - 0.3 inches taller than standard for clear sight picture
- 27.9 oz weight - balances well with suppressors adding 5-10 oz
- Includes 15-round and 24-round magazines - 39 rounds total capacity
Trade-offs
- No thread protector included - $25-35 additional purchase required
- Optics plates sold separately - adds $45-60 per footprint
- Trigger pull variance 4.5-6.7 lb - wider range than some competitors
Expert review
Key attributes
| upc | 845737011611 |
| manufacturer | FN America / FN Herstal |
| manufacturer part number | 66-100746 |
| action | Striker Fired |
| barrel length | 4.50" |
| caliber/gauge | 9mm |
| capacity | 10 + 1 |
| safety | No |
| shipping weight | 3.7 |
| sights type | 3-Dot Night/Suppressor Height |
| slide description | Optic Cut/Serrated |
Frequently asked questions
- Is it compatible with Trijicon RMR optics?
- Yes, the FN Low-Profile Optics-Mounting System accepts Trijicon RMR footprint optics directly. You'll need to purchase FN's specific RMR mounting plate separately, which typically costs $45-60 and installs with the provided torque screws in about 5 minutes.
- Does it fit standard FN 509 holsters?
- The tactical model requires holsters designed for optics and suppressor-height sights. While it shares the standard FN 509 frame dimensions, the threaded barrel and taller sights add approximately 0.4 inches of clearance needed. Safariland 6390RDS models with optic cuts work perfectly.
- How long does shipping take to FFL dealers?
- Most FFL shipments process within 2 business days and deliver within 3-5 additional days via FedEx or UPS. We recommend confirming your dealer's acceptance of online transfers before ordering, as some require advance notification for compliance tracking.
- Does this work with SilencerCo Omega 9K suppressors?
- Absolutely - the 1/2x28 thread pattern matches SilencerCo's standard pistol mounts. The 4.5-inch barrel provides optimal dwell time for the Omega 9K, and we've recorded consistent ejection patterns with 124gr ammunition at our test range.