Pistol Smith Forum banner
1 - 5 of 5 Posts

·
Registered
Joined
·
94 Posts
Discussion Starter · #1 ·
Recently my Sig P220 has been having failure to fires. An examination of the unfired case finds that the primer strike is not centered. (This has occurred with multiple brands of ammo). Does anyone know what this means and what, if any, repairs could fix this?
 

·
Registered
Joined
·
54 Posts
How much off center is the indentation? Has it always struck off-center? I think the firing pin might be broken where one piece strikes the other, but the piece closest to the primer travels at an angle other than 90 degrees toward the primer, thus deflecting the blow and causing the malfunction.

If the firing pin is broken, it can be easily replaced by removing the roll pin holding the breech-block in the slide, removing the breech-block, replacing the firing pin, and reassembly using new roll pins. Reusing the old roll pin will cause the pin to slide out under recoil. All you need is the correct size punch, and $20 worth of parts from Sig. It will take you 5 minutes.
 

·
Registered
Joined
·
94 Posts
Discussion Starter · #3 ·
Thanks for your reply and the help. To clarify, the primer strikes are typically not off-center. However, when I have failure to fire, the strike is off center. I've noticed a gradual increase in the number of FTF's I've had. I'd estimate I'm having 3-4 every two hundred rounds. I've had this experience with both PMP and PMC ammo.
 

·
Registered
Joined
·
54 Posts
Try this:
Lock the slide back, and hold the pistol muzzle down on the table.
Depress the firing pin block with your index finger (the hand holding the pistol)
Depress the firing pin with a pencil until it portrudes from the breech-face.
Retract the firing pin by relieving the pressure with the pencil.
If the firing pin retracts, then it is not broken.


Another possibility is the ammo. Sometimes, in cheap ammo, the primer pocket is out of center, and an off center strike might fail to fire. PMP uses real hard primer cups, so an off center strike might fail to fire.


Off-center primer pockets also plague Federal ammo, but their primers are very soft.
 

·
Registered
Joined
·
248 Posts
I have seen several SIG's lately with a variety of problems. All of the problems have been related to dirt. These weapons get used alot and field stripped. THey had not been detail cleaned in 2000+ rounds. A good detail cleaning fixed them all up.
 
1 - 5 of 5 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top