Owner’s Manual 2020

35
Note: The FN 509 has been tested to ensure safe operation. The reliability of
the pistol may be affected by the installation of a suppressor or muzzle
device.
9.9 INTERCHANGEABLE BACKSTRAPS
The FN 509 has been designed to use
interchangeable backstraps that
allow the pistol to be adapted to fit
your hand better (Figure 36).
Backstraps provided vary by model.
9.10 FN OPTICS MOUNTING SYSTEM
(APPLICABLE ONLY TO PISTOLS WITH FN OPTICS MOUNTING SYSTEM)
The FN optics mounting system
(Figure 37) allows for the mounting of
a variety of optical sights to the slide
of the FN 509 without modification to
the slide. When an optical sight is
not installed a slide cap is installed
in its place. Some slide caps include
sight protectors that prevent damage
or unintentional movement of the rear
sight and can be used for the one
handed manipulation of the slide.
10. SIGHT ALIGNMENT
NOTE: The sight alignment described is for the standard sights provided
with the FN 509 pistol. Alternate sight options may have different sight
alignment requirements. Please refer to any special instructions provided
with your alternate sights.
FIGURE 36
Interchangeable backstraps.
FIGURE 37
FN optics mounting system.