Changing Hammer Springs in Beretta Px4 and 92FS Pistols
Owners of Beretta model 92FS and Px4 Storm pistols who want
to lighten up the trigger pulls on those pistols can do so by changing each
pistol's hammer spring. The operation only takes a few minutes, doesn't require
any special tools, and can be done by anyone.
Px4 Storm Pistol
For a model Px4 Storm pistol, use the Wolf replacement hammer
spring for a 1911 model pistol. Wolf offers these in 18lb and 20lb sizes. I
installed an 18lb spring in my Px4.
How to change the hammer spring on a model Px4 Storm pistol:
Remove the magazine and pull out the U-shaped retaining clip. Notice that the top part
of the clip's legs are bent slightly toward the muzzle. You must replace it the
same way during step 9.
Remove the backstrap to expose the roll pin holding the end cap in place.
Place a thumb or finger over the cap and hold it in place while pushing out the roll
pin.
Slowly release the cap until the spring behind it is no longer compressed.
Pull out the existing hammer spring, but take note that the hammer strut is
positioned inside the spring. Also note that the ends of the spring are flat.
I'm not sure if it's required, but I flattened the ends of the Wolf spring
(using a small file) until they matched the original spring.
All parts removed:
Insert the new hammer spring, taking care to place the spring over and around the
hammer strut.
Reinstall the end cap, and while depressing it under tension, replace the roll pin.
Reinstall the backstrap.
Reinsert the U-shaped retaining clip, aligning it so that the bent area is facing the
muzzle.
Press the clip firmly into place.
92FS Pistol
For a model 92FS (or M9), use the hammer spring made for a
Beretta 92D model pistol.
How to change the hammer spring on a model 92FS pistol:
Remove the magazine and grip panels.
Locate the roll pin holding the end or lanyard cap in place.
Place a thumb or finger over the cap and hold it in place while pushing out the roll
pin.
Slowly release the cap until the spring behind it is no longer compressed.
Pull out the existing hammer spring, but take note that the hammer strut is
positioned inside the spring.
Insert the new hammer spring, taking care to place the spring over and around the
hammer strut.
Reinstall the cap, and while depressing it under tension, replace the roll pin.
