FN 509 Tactical 9mm FDE 4.5in Threaded — 17/24rd Mags

Description

The FN 509 Tactical 9mm FDE 4.5in Threaded — 17/24rd Mags is a full-size, striker-fired pistol built on FN’s proven 509 platform. It comes ready for a suppressor and red dot right out of the box, with a 4.5-inch cold hammer-forged barrel, suppressor-height night sights, and two magazines.

Manufacturer	FN America
Model	509 Tactical
Caliber	9mm
Barrel Length	4.5 inches (threaded 1/2×28)
Finish	Flat Dark Earth polymer frame, black nitride slide
Weight	26.9 oz (unloaded, per manufacturer specs)
Capacity	17 rounds (flush) + 24 rounds (extended)
Sights	Suppressor-height tritium night sights
Condition	New

Key Features

• Threaded barrel with O-ring cap — The 4.5-inch cold hammer-forged stainless barrel is threaded 1/2×28 and includes a locking thread cap with an O-ring. Why it matters: You can mount a suppressor or compensator securely and keep the cap from backing off during live fire.
• Low-profile optics mounting system — FN’s system lets you mount popular miniature red dots like the Trijicon RMR, Leupold DeltaPoint Pro, and Holosun 407C/507C directly to the slide, no milling required. Why it matters: You can switch between irons and a dot without sending the slide to a machine shop.
• Suppressor-height night sights — Three-dot tritium night sights co-witness through most red dots and clear suppressor cans. Why it matters: Your sight picture stays usable whether you’re running a can, a dot, or just the irons.
• Enhanced grip texture — The FDE frame uses FN’s aggressive texture with deep grooves and a high tang. Why it matters: You get a locked-in grip even with sweaty hands or while wearing gloves, and the high tang helps control muzzle rise.
• Two magazines included — Ships with one 17-round flush-fit mag and one 24-round extended mag, plus a soft pistol case. Why it matters: You get a range-ready setup and a backup high-capacity mag for classes or competition.

Who It’s For

This pistol is for the shooter who wants a duty-ready 9mm that can do it all — home defense, range shooting, and suppressed or red-dot use — without needing aftermarket parts. It’s also a solid choice for new gun owners who want one pistol that can grow with them as they add accessories.

Pros & Cons

• Pro: Optics-ready straight from the factory — no slide milling cost or wait.
• Pro: Suppressor-height night sights co-witness with most red dots and clear suppressor cans.
• Con: The aggressive grip texture can be rough on bare skin during all-day concealed carry. A lot of folks wear an undershirt or use a grip sleeve.

How It Stacks Up

Feature	FN 509 Tactical	Zev Technologies OZ9	Agency Arms AOS Glock 17
Barrel length	4.5″ threaded	4.5″ threaded	4.5″ threaded
Optics mount	Low-profile system (no plate needed for RMR/DPP)	Zev optics plate system	Agency AOS plate system
Magazines included	2 (17 & 24 rounds)	2 (17 rounds each)	3 (17 rounds each)
Price	$833.53	$1,200+	$1,100+
Frame material	Polymer	Polymer with steel chassis	Polymer

Frequently Asked Questions

Does the FN 509 Tactical come with a suppressor-height front sight?

Yes. It ships with suppressor-height tritium night sights front and rear. They co-witness with most micro red dots and are tall enough to see over a suppressor.

Can I mount a Holosun 507C directly without a plate?

Yes. The slide has FN’s Low-Profile Optics Mounting System that accepts Holosun 407C/507C, Trijicon RMR, and Leupold DeltaPoint Pro footprints without an adapter plate. You just need the correct screws (included).

What thread pitch is the barrel?

It’s 1/2×28, the standard 9mm thread pitch. Most 9mm suppressors and compensators will fit directly.

Does the 24-round magazine work with other FN 509 models?

Yes. The 24-round extended magazine is compatible with all FN 509 full-size and compact models. It will stick out a bit on the compact frame, but it runs reliably.

Is the trigger the same as the standard FN 509?

Yes, it uses the same striker-fired trigger with a blade safety. Pull weight is around 5.5-6.5 lbs per FN specs. It’s duty-grade — not match-grade, but crisp and repeatable.

Trust & Service

• ✅ Nationwide delivery (all 50 states)
• ✅ Ships in 1-2 business days
• ✅ 30-day return policy
• ✅ Secure checkout

Last updated: April 2026

More options: Semi Auto Handguns | FN Handguns | Suppressor-Ready Pistols