Light Strike Fixes
What follows is a "re-write" of Glenn Higa's original treatise by Chandler Bates III:
The P-11 firing mechanism is designed for safety. A heavy spring around the firing pin keeps it from contacting the primer. The gun can fire only when the trigger is pulled all the way to the rear. The trigger is connected to the hammer by a transfer bar, so pulling the trigger pushes the hammer rearward. When the hammer has traveled far enough, it slips off the transfer bar. The hammer springs forward at high speed and strikes the firing pin with sufficient force to overcome the firing pin retaining spring.
Upon firing, the slide travels backward, pushing the hammer back again. Since the hammer does not lock back (as it would with a single action), it follows the slide forward coming to rest against the firing pin. The spring must keep the pin from traveling forward far enough to fire the newly chambered round (slam fire). Even if the gun is dropped it
will not fire because the mass of the hammer/firing pin is so small that, even with the mass of the gun, dropping from a great distance will not overcome the spring.
When users report "light strikes", it is probably due to friction around the firing pin. The pin might have rough surfaces or be in contact with the firing pin retaining screw. Glenn Higa's instructions below reduce friction by removing manufacturing burrs and ensuring that the pin is set properly in the channel. The firing pin spring should not be modified for safety and liability reasons. If this procedure does not eliminate light strikes, try a new firing pin spring (part # P-11-172) from Kel-Tec, or send the gun back for warranty repair.
Firing Pin LightStrikes Fix
by Glenn Higa
The Kel-Tec P-11 design is elegantly simple and very efficient. The largest obstacle to proper firing pin operation is friction. The goal here is to reduce friction. Refer to your exploded diagram for part names. Read through and understand this guide entirely before beginning. The procedure takes about 45 minutes. Tools required:
- Allen wrench for firing pin screw (3/32)
- Drill bits: 3/32, 5/64 (or is that 3/32?)
- Fine Emery cloth or Dremel polishing
- Lubricant (MilSpec1 or Brownell's Action Magic II)
- Loctite (Blue, Medium strength)
1. Make sure the gun is unloaded and field strip it. Remove the firing pin from the slide by depressing it and removing the firing pin retaining screw from the top of the slide. Use caution: the firing pin is under spring pressure and will eject itself out of the slide, usually landing in some inaccessible place in your workshop or home.
2. Lightly chamfer both sides of the firing pin hole by finger turning a 3/32" drill bit, which is slightly larger than the hole. Do not create a large bevel, just clean up burrs and break the sharp edge left by the machining process.
3. Gently clean up the bore of the firing pin channel (the hole that the firing pin and spring normally reside in) by working a 5/64" drill bit back and forth in it. It is not necessary to turn the bit since the spiral of the bit will provide the cutting action. (Or maybe that's supposed to be a 5/32 bit?)
4. Smooth or polish the firing pin. Break the sharp edges running perpendicular to the direction of movement. Fine Crocus or Emery cloth stroked in the direction of movement produces good results. Do not create a bevel where the firing pin stop surface (the surface that the firing pin retaining screw contacts) meets the circumferential surface
of the pin. A bevel here may increase the chances of the firing pin getting wedged "back", resulting in a non-firing
gun. Also, do not reshape the tip of the firing pin.
5. Slightly round the sharp edge on the beveled end of the firing pin screw since it may come in contact with and cut the firing pin.
6. Clean and degrease the firing pin channel, firing pin retaining screw threads in the slide, and the spring, pin and screw.
7. Place the "springless" pin in the channel and check for smooth movement. Make sure the flat surface of the firing pin is exactly parallel with the top of the slide.
8. Start the firing pin screw into its threads. Depress the firing pin flush with the back of the slide and carefully turn the screw in just until it contacts the flat surface of the firing pin. Back out the screw enough to gain
a slight clearance so it does not contact the firing pin flat surface (adding friction). If your gun is like mine, there will be enough space between the pin and screw to allow the pin to rotate about 20 degrees or so. I feel this spacing is just about perfect. It provides enough space to prevent jamming from dirt while providing the proper bearing surface between the firing pin stop surface and the firing pin screw. Now carefully count the number of turns (including a fraction) required to back the firing pin screw out of its threads, and write it down.
9. Remove the pin, and replace the spring on the pin. If your spring has a smaller end, install it first onto the pin. I feel that placing the larger end in the channel cup will center the spring better and result in less spring to pin contact. Place the pin/spring in the channel and check for smooth movement.
10. If all is well, remove the spring/pin and lubricate. I used Brownell's Action Magic II with very good results. Before lubricating the channel, insert the firing pin screw in the slide about 2/3 the way (your count)
to block the threads on the screw and slide from lubrication. This will prevent lubrication from reaching these threads and reducing the effectiveness of the Loctite (step 12). After lightly lubricating the channel, remove the firing pin screw and degrease it again.
11. Install the pin/spring assembly into the channel. Since the spring is coiled, it will tend to twist the firing pin counterclockwise when the spring is compressed. Compensate for this by starting the pin into the channel rotated at about a 45 degree angle (top) to the right. It is important to get the flat side of the firing pin directly parallel to the top of the slide when the spring is compressed. Otherwise, the spring may twist the firing pin in the channel and cause continual drag against the firing pin retaining screw.
12. Using Blue Loctite, place a drop on the firing pin screw threads and start the screw into the slide one full turn. Insure that the Loctite doesn't get into the firing pin channel. While depressing the firing pin with the "flat" facing the screw, turn the screw in the rest of the way (you counted the turns exactly, remember?). If screw solidly contacts pin, back off a fraction of a turn. Make sure the pin moves freely in its channel and does not drag against the retaining screw while the Loctite sets up.
13. Test fire your P-11 using the same ammo with which you experienced light strikes. Also try some Blazers as they are known to have hard primers. Make sure you test with whatever ammo you choose for self defense.
That's it! Friction has been minimized and light primer strikes should be a thing of the past.