Two interchangeable backstraps

Two 15-round magazines

Owner’s manual

Locking device

FN logo soft pistol case

FN America FN509 MIDSIZE 509 9mm 66-100463

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FN America FN 509, Semi-automatic, Striker Fired, Mid Size, 9MM, 4" Barrel, Polymer Frame, Black Finish, 2-15Rd Magazines, 3 Dot Sights, Non-Manual Safety 66-100463


Upgrade your EDC with the all-new FN 509® Midsize. This ideal combination of a four-inch slide and barrel with a midsize frame retains full-sized pistol performance in an easily-concealed package. The 9mm pistol ships standard with 15-round capacity and is compatible with all FN 509 magazines with use of a sleeve. The improved controls aid in manipulation, the new improved texturing on the two included backstraps provides better recoil management and a new, flatter faced trigger allows for more controllable trigger press and cleaner break.



  • CALIBER: 9mm
  • OPERATION: Double-action
  • MAG CAPACITY: 10 or 15 Rd.
  • WEIGHT: 26.5 oz.
  • TWIST RATE: 1:10" RH
  • HEIGHT: 5.2"
  • WIDTH: 1.35"
  • TRIGGER PULL: 5.5 - 7.5 lb.
  • SIGHT RADIUS: 5.79"


Full-sized performance in a concealed carry package

Striker-fired autoloader

Double-action operation

Fully ambidextrous controls

Offered as a non-manual safety model

Fixed 3-dot luminescent sights (standard)

Fixed 3-dot green tritium night sight available (LE ONLY)



Easily racked, combat-style sights

External extractor; loaded chamber indicator

Improved front and rear cocking serrations



Cold hammer-forged stainless steel

Recessed target crown

Polished chamber and feed ramp



Polymer construction with replaceable steel frame/slide rails

Enhanced grip textures which enables faster follow-up shots in all conditions

Interchangeable backstraps

MIL-STD-1913 accessory mounting rail

Improved flatter face trigger



Fully ambidextrous slide stop lever and magazine release



High visibility, low-friction follower; polymer base with black finish

Compatible with FN 509 17-round and 24-round
magazines with appropriate magazine sleeves



Two interchangeable backstraps

Two 15-round magazines

Owner’s manual

Locking device

FN logo soft pistol case


Condition: New
Manufacturer: FN America
Model: 509 Midsize
Caliber: 9mm Luger
SKU: 845737010010
MPN: 66-100463
UPC: 845737010010
Vendor: Gunprime
Reviews (17)
By Ej on 09/08/22
Fn 509 Midsize is great

I’ve always wanted a FN finally got one and don’t regret it. Feels good in my hands. Has a nice weight to it. Overall a great gun

By Vic on 09/30/20
I like gunprime and their services. They delivered my handgun right away and I got it within couple days. Great service!

My handgun was brand brand new, looked exactly what I saw on the gunprime website. Great quality gun and super service, thanks

By Private on 09/25/20

Easy to handle, and easy to target

By Mike B on 09/19/20
Nice gun. Awesome communication from Gunprime.

Shoots and cycles well. Fits the hand awesome as all my FN's do. Seems a bit low at close range (7yds or less), but further out it's fine. I may be pulling it. Time will tell. Quick shipping and Gunprime alerted me every step of the way. I really appreciate having that info.

By Wallace on 09/18/20
great and fast service

This is the second FN 509 I have own. The first one I traded and almost instantly I regret it. Couldn't find one for months until I came across Gunprime. I ordered it and 4 days later I was using it. Fast, accurate service and not a single issue with the gun or the seller.

By Mad Man on 09/03/20

Great Service and Fast Shipping

By Jghost on 09/02/20
Great pistol!

Great pistol, I like everything about it, I would definitely purchase another when the time is right

By Daniel Davenport on 08/28/20

I dislike that the Company didn't put all three Back Straps in the FN 509 Midsize, haven't had a chance to shot it yet had it about two Weeks.

By Brian on 08/23/20
Great gun from a great vendor

The FN 509M has outstanding controls. I love the easy to use slide release, which is ambidextrous. The mag release is also ambidextrous.

Gun feels great in hand, and fires accurately. Nice sights which illuminate in darkness. Also has a built in picatinny rail for easy light or other accessory mounting.

Gunprime shipped very quickly, as they have on other orders also.

By Alex on 07/17/20
Solid all around

Perfect size, good feel, clean trigger. Great buy.

By LeeJohn on 07/17/20

Amazing handgun

By Scstewart77 on 06/16/20
Fast shipping, pistol is excellent

The pistol feels great in hand and functions flawlessly. Shipping was fast, arrived earlier than expected. I will definitely buy from gunprime again.

By Finally a true Glock Killer on 06/16/20
Immediately Replaced My EDC Glock 19

I have now had this gun for several months and wish I had looked at the FNs sooner. The ergonomics and shootability of this pistol far exceed the Glock 19 I have carried religiously for years! I Could not believe how good the gun fits in my hand, and the pure pointability of it. I have used a Glock 19 in various combat situations in the Middle East and although I have never like the looks of it, it worked every time. This gun is superior in most every way. Feels better, shoots better, the trigger out of the box is superb. I owned Sig 320, CZ P07 and P10, Beretta 92F and others and this is my favorite pistol of all time! In fact not long after I bought this I also ordered the full size for a house gun. It is almost exactly the size of a Glock 19 so IWB carry is good.

This is by far the best out of the box pistol on the Market today.

By Tanner f. on 06/16/20
Great overall

I really like this gun. It's my first carry pistol so overall it's very reliable.

By Sirabe on 06/15/20
Great feel great weight great look awesome feel.

I just love the gun. I’m now looking for a subcompact now so if you have ideas please let me know

By Jim on 06/06/20
Great gun

Great gun and great price.

By Dookie Eater on 06/05/20
Absolutely Solid!

This is my new favorite pistol...out of the box this is by far the most bang for your buck I feel. There isn’t really much bad I can say about it. For my hands the ergonomics are just awesome. I also have a Walther P99 that I pretty much compare every pistol to because it just feels so good in my hands and the 509 midsize to me is right up to par with that. I typically carry a Glock 23 with is pretty much exactly the same size but when I pick up a Glock I don’t pick it up to shoot it, I pick it up, put in a holster and go about my day...the 509 midsize on the other hand I pick it up and just wanna go fire it. It’s a gun that the second you pick it up is the second you also decided to go to the range that day haha

Over all it’s a great firearm, it’s beautiful to look at, it feels great, it fires great, it’s very reliable, it’s easy to conceal and carry all day and it’s a blast at the range. The ONLY thing that you need to be aware of is the fact the the trigger is a little gritty at first BUT that went away about 150, 200 rounds in.

Don’t think about it, don’t be dumb and just buy it.

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