THE 9MM FN 509 AND THE 9MM FN 509 MIDSIZE

Article By Nick Jacobellis

I first became familiar with the FN 509 series of pistol when I field tested the model that

accommodates a 17 round magazine. I hesitate to call this the full size 509, because this model has the

same 4 inch barrel as the FN 509 Midsize. Surprisingly, the FN 509 Midsize model that accommodates

a 15 round magazine or a 10 round magazine weighs 26.5 pounds, while the “standard” FN 509 that

accommodates a 17 or a 10 round magazine weighs 26.9 pounds when unloaded.

As far as ergonomics are concerned, the grip portion on the 509 frame includes different 

patterns of texture, that combine to provide a very comfortable to grip when shooting with bare hands.

The 509 is also supplied with an additional interchangeable backstrap, that makes it possible to contour

the grip to your hand size.

I also found the slide on the FN 509 Midsize to be incredibly easy to manually retract/operate, 

which in my case is a concern, now that I’m older and have a touch of arthritis in both hands. All 509

variants also have very user friendly slightly angled front and rear slide serrations. The 509 series of

pistols also have superb 3 dot luminescent sights and very well placed ambi controls.

                           CONCEALED CARRY  

While evaluating the FN 509 Midsize I found this pistol to be easy to carry concealed, while 

using an inexpensive Uncle Mikes Number 15 Inside the Pants Holster. Even though these soft holsters

do not permit you to execute a one handed return to the holster, they do enable a handgun to be

carried about as close to the body as possible. Since life is all about trade offs, I gravitate to using an

Uncle Mikes Inside the Pants Holster for super concealed carry applications, especially when casually

dressed in warm weather. I am also a huge fan of De Santis Holsters and have a number of De Santis

Inside the Pants and High Ride belt holsters. During my law enforcement career I also utilized a

De Santis shoulder holster that was very comfortable to wear for hours on end.

As a side note I should mention, that when a U.S. Special Forces operator, who is a close friend 

of my family, was deployed to a high threat location overseas, where he needed to carry concealed, he

carried his issued 9mm Compact Personal Defense Weapon in one of the Uncle Mikes No 15 Inside the

Pants Holsters that I gave him as a gift. My recommendation to carry his issued Compact Personal

Defense Weapon in an Uncle Mikes No 15 proved to be very worthwhile advice, when it became more

important to conceal his issued 9mm pistol, than it was to wear a rig that allowed the operator to easily

return his pistol to a holstered position.

                          SHOTS FIRED   

While all premium brand firearms have the capability of being extremely accurate in properly 

trained hands, for various reasons some shooters can be exceedingly more proficient with certain

firearms. This has been proven to me time and again, when I have trained with and field tested

different makes, models and calibers of firearms. For various reasons that I explain in this evaluation,

the FN 509 has proven to be one of those pistols that is incredibly easy for me to shoot with

tremendous precision. This included being able to effortlessly engage small targets at more extreme

distances, with a FN 509 and the 509 Midsize model from a standing unsupported position. I attribute

this to the 509s superb ergonomics, superb sights, superb striker fired trigger system, as well as the

overall weight and balance of this compact pistol.

                  CLOSING REMARKS

The FN 509 and the FN 509 Midsize are premium brand striker fired 9mm pistols that are 

designed with a great deal of thought and attention to detail. The fact that FN is a leading producer of

a wide variety of military and law enforcement firearms is evident by the high quality fit, finish and

performance of 509 pistols.

SIDEBAR: When I evaluate a premium brand firearm my first concern is ease of operation. I consider

this a priority, because it doesn’t pay to purchase, train with and carry a firearm that is difficult or

uncomfortable to operate. If you can’t easily manually operate the slide on a pistol don’t buy it. If you

grip a pistol and it doesn’t feel comfortable in your strong and weak hand don’t buy it. If you have any

difficulty cycling or engaging the trigger on an empty/unloaded pistol don’t buy it. If you can’t easily

disassemble a pistol or any other firearm, so it can be properly cleaned and maintained, don’t buy it.

For the record, the 9mm FN 509 and the 9mm FN 509 Midsize are two pistols that are about as user

friendly as a firearm can be.

About the author:
Nick Jacobellis is a Medically Retired U.S. Customs Agent and a former NY police officer who was physically disabled in the line of duty while working undercover as a federal agent. To date, the author has published over 205 magazine articles and ten action-packed nonfiction, historical fiction, and fiction books: Controlled Delivery Books One and Two, The Frontline Fugitives Books I, II, III, and IV, Buck Banderas U.S. Marshal Books One and Two and A Special Kind of Hero. These books have received 5 Star reviews and are available on Amazon.com (US), and (UK). The K9 Academy is the author’s 10th book. The author was born and raised in Flatbush section of Brooklyn N.Y. and has an BS Degree in Police Science from John Jay College of Criminal Justice.

SPECS FN 509 MIDSIZE
CALIBER: 9mm
OPERATION: Double-action
MAG CAPACITY:10 or 15 Rd.
• WEIGHT:26.5 oz.
• BARREL LENGTH:4.0″
• OVERALL LENGTH:7.4″
• TWIST RATE:1:10″ RH
• HEIGHT:5.2″
• WIDTH:.35″
• TRIGGER PULL: 5.5 – 7.7 lb.
• SIGHT RADIUS:5.79″
• Trigger: Striker Fired.
Fully ambidextrous controls
Offered as a non-manual safety model
Fixed 3-dot luminescent sights (standard)
SLIDE
Easily racked, combat-style sights
External extractor; loaded chamber indicator
Improved front and rear cocking serrations
BARREL
Cold hammer-forged stainless steel
Recessed target crown
Polished chamber and feed ramp
FRAME
Polymer construction with replaceable steel frame 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
OPERATING CONTROLS
Fully ambidextrous slide stop lever and magazine release
MAGAZINE
High visibility, low-friction follower; polymer base with black finish
Compatible with FN 509 17-round and 24-round
magazines with appropriate magazine sleeves
SHIPS WITH
Two interchangeable backstraps
Two 15-round magazines or Two 10-round
Owner’s manual
Locking device
FN logo soft pistol case

THE FN 509
MAG CAPACITY: 10 or 17 Rd.
• WEIGHT: 26.9 oz.
• BARREL LENGTH: 4.0″
• OVERALL LENGTH: 7.4″
• TWIST RATE: 1:10″ RH
• HEIGHT: 5.56″
• WIDTH: 1.35″
• TRIGGER PULL: 5.5 – 7.7 lb.
• SIGHT RADIUS: 5.79″
TRIGGER: STRIKER FIRED.

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