FTF-Light Strike. Can a new gun be short stroked?

Discussion in 'P-3AT' started by bluesman, Jun 17, 2009.

  1. bluesman

    bluesman New Member

    43
    Apr 5, 2009
    I searched and found several posts on Failure to Fire FTF due to light primer strikes, and it seems the advice was to upgrade to the new hammer block which my late model (2008) gun has, or clean the firing pin and associated area.

    I have had 3 FTF due to light strikes . 2 on Hornaday JHP rounds, and one today on a Winchester White Box round. I reloaded the WWB round and it fired normally.

    These 3 FTF occurrences are out of less than 50 rounds, leaving me a bit concerned. Today I was rapid firing and I may have been the last time I fired the gun with the Hornaday's as well. I am a Glock guy and have some IPSC experience, which means I like to double tap with short trigger strokes. My P-3AT requires (as you know) a long, long trigger pull almost back to the grip to fire.

    According to the previous threads I read, I should not be able to induce this short stroking with my late model gun with the new trigger block. Is that true??? :-/
     
  2. billjohnso20

    billjohnso20 Active Member

    Dec 7, 2008
    Re: FTF-Light Strike. Can a new gun be short strok

    Definitely check the firing pin channel. If it's clean and it still fails, it may require a trip home to momma.
     

  3. Possumgravy

    Possumgravy Guest

    Re: FTF-Light Strike. Can a new gun be short strok

    I agree with the others. You shouldn't be able to short stroke it. Test it and see if it can be short stroked--maybe you got one with the older hammer block. Another thought is that you may have over stretched the hammer spring if you have had it out. You may just need a new spring.
     
  4. PF9Newbie

    PF9Newbie New Member

    Nov 22, 2008
    Wisconsin
    Re: FTF-Light Strike. Can a new gun be short strok

    I don't think the revised hammer block entirely prevents short stroking, it just reduces any tendency to do so. But in this case, since you are used to a short trigger pull, and using double taps, it may be possible that you are indeed short stroking the trigger sub-consciously, and just not really used to the very long required trigger pull here. Muscle memory (int this the trigger finger) can take some time and practice to overcome, along with very deliberate efforts to do so. Still could be a mechanical issue of course, but first I would work with it, being very concious and deliberate to ensure full stroking of the trigger and to be that ingrained shooting habits are not the cause.

    Jim R
     
  5. Sangueffusor

    Sangueffusor New Member

    May 13, 2007
    Indiana
    Re: FTF-Light Strike. Can a new gun be short strok

    Actually, it does. You would probably break the trigger if you applied enough force before you could ever short stroke it.
     
  6. bluesman

    bluesman New Member

    43
    Apr 5, 2009
    Re: FTF-Light Strike. Can a new gun be short strok

    I took apart and found issues with the firing pin assembly burrs etc, thanks for the help!!!
     
  7. bluesman

    bluesman New Member

    43
    Apr 5, 2009
    Detailing the firing pin assembly

    I was having rounds that failed to fire due to light strikes as per my previous (short stroking) post. I started evaluating the firing pin and when I tried to simply press it in simulating the hammer striking it it had a slight hang-up (notchyness) to it about half way depressed. I took it apart and found the screw that holds it in pretty mashed down (from dry firing I guess) and also there were small burrs in the firing pin chamber in the set screw area that I took out with a No. 20 drill bit per a previous post. I finish sander with 600/400 grit, and Pin slides smooth now. One issue solved!

    Q1? The flat surface of the firing pin where the screw nests was not exactly machined flat. It has a nice flat surface in the middle and then drops into a little rounded trough on both ends of the slot, is this normal??? Will it effect anything? Should I get a new pin?

    Q2? Please help me understand the design of the set screw and slotted firing pin. Do you simply screw in the screw (with locktite) and back it off a half a turn to reinstall? The primer stops the pin moving forward unless there is no cartridge in the chamber, then the set screw is what stops the pin each time the hammer dry-fires it?

    Q3? Someone had a ball bearing modification that sounded cool is this a good idea??

    thanks, I think I am close to getting my baby back in top fighting shape!! ;D
     
  8. JFB

    JFB New Member

    Jul 25, 2005
    Re: Detailing the firing pin assembly

    Q1
    - not sure what you mean.  the 'flat' is milled with a ball end bit.  thus there is a radius at each end

    Q2
    -yes if 1G
    -no if 2G

    Q3
    -i remember that post, and looking at the dimensions, but don't recall if it actually worked
     
  9. bluesman

    bluesman New Member

    43
    Apr 5, 2009
    Re: FTF-Light Strike. Can a new gun be short strok

    Q1. At the ends where the tool started or stopped milling it dropped below the level of the flat area creating and a radius. I wish I had a magnifiying glass handy so I could take a pic.

    My Gun is less than a year old so what is the proper way to install the set screw?
     
  10. JFB

    JFB New Member

    Jul 25, 2005
    Re: FTF-Light Strike. Can a new gun be short strok

    [​IMG] if you have a set screw,you have a 1G


    [​IMG] if you have a button head screw,you have a 2G

    with the 1G the set screw is turn till it makes contact with the flat on the FP, then needs to be backed off a little to provide clearance for FP to slide by.  since there is no force on the threads to keep them from backing out, a drop of locktite is required

    with the 2G, the button head screw holds the extractor spring hard against the slide.  the head of the cap screw is torqued to 70% yield (~12 inch-lbs) and thus locktite is optional (but recomended).  the lenght of the threads are extremely important and determines the clearance to the FP flat


    Q1

    [​IMG]
    my pins are like the black outline.  are you saying you have a red areas machined.  if so, that might be a good improvement to the design.

    the radiuses for the black outline would wedge into the screw end.  by having the reliefs cut like the red, only the side of the screw is impacted. only concern would be the transferr of impact from the hammer if the reliefs are too deep and thus allow bending
     
  11. bluesman

    bluesman New Member

    43
    Apr 5, 2009
    Re: FTF-Light Strike. Can a new gun be short strok

    WOW, thanks for the graphics!!!  Yes I have a Button head 2nd gen and it has a dot of yellow locktitie on it. I will get a new one since mine is pretty mashed up on the end.

    And yes, your drawing exactly represents what I am seeing (but exaggerated of course) on my firing pin. The actual depth of the radius's are only maybe .010" below the flat surface. 

    I am assuming a very light lube and reinstall  :D
     
  12. bluesman

    bluesman New Member

    43
    Apr 5, 2009
    Re: FTF-Light Strike. Can a new gun be short strok

    The mother ship is sending me a new screw and I should be in my way!