25th Anniversary K9
25th Anniversary K9

Announcement

Collapse
No announcement yet.

A used P380: the good, the bad, the ugly, and a happy ending.

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • A used P380: the good, the bad, the ugly, and a happy ending.

    Well, a while back I bought a used P380. The shop let me shoot a few rounds through it and all was good. It fed and ejected without issue plus I was accurate with it.

    The bad: fast forward about 50 rounds after I purchased it and I started to get light strikes. I did a quick visual and it appeared that the striker spring had failed.
    The shop's new gunsmith verified it and said he'd get a spring on order. I decided to do likewise along with some spare parts. I received my parts in good order from Kahr. That was a good thing because the gunsmith dropped the ball on his order. I installed the new spring, but continued to have some light strikes. I also installed a new striker block. This didn't help with the light strikes, but because it was slightly oversize I ended up with a much better "fit' than with the original part. Another part I ordered was a PM9 striker spring, so I tried it in the P380; shot a quick 30 rounds without a misfire, but the slide would move rearward as I pulled the trigger (heavier striker spring overcoming the recoil spring). I didn't like this, but the results had me thinking the spring might be the issue. I played around with P380 striker spring: stretching it, putting washers between it and the guide rod, I even cut some coils off.
    I still had light strikes.
    Finally it occurred to me that perhaps the cocking cam was the issue. I thought that it might not be lifting the striker block enough, possibly high enough that the CM9 striker spring could power the striker past it, but not enough for the 380 striker spring. Grasping at straws, I ordered a cocking cam and another 380 striker spring (curiously, this spring proved a little stronger than the first one I received).

    (L to R: broken 380 spring, cut down 380 spring, full length 380 spring, PM9 spring)
    The ugly; The parts arrived and I proceeded to disassemble the frame. Removing the side plate, I immediately noticed that the bottom screw was not that tight...with the plate off, it looked like both screw holes had been drilled twice...not good.

    I decided to deal with that later and continued with the dis-assembly. I made a small, non-marring taper punch from a bamboo chopstick and used this with an arbor press to remove the trigger axis pin (I hold the punch in place during this operation). The press is only needed to start the pin out, once it's past the retaining pin a brass rod can complete the job.



    I used a dental pick to pry the cocking cam axis pin up enough to pull it out.


    ...to be continued
    Last edited by gb6491; 11-24-2017, 09:40 PM.
    sigpic

  • #2
    Houston we have a problem!
    Comparing the cocking cams, there's a considerable difference in profile, but the new cam did have more "lift" on the striker block lobe.

    The problem is that the lobe is not as wide as that on the old cam...well.... actually the bigger problem is that this results in the whole cam being not as wide as the old cam.


    Bummer..I planned to call Kahr about this the following day, but sitting there staring at the parts I decided to look through my accumulated washer stash. This search turned up some gold ...OK, so it's brass, but it works (precise fit on the axis pin)!. I like how this settled out as the cocking cam now has metal bearing surfaces on either side of it and is aligned with the striker block.


    ...to be continued
    sigpic

    Comment


    • #3
      On to the screw holes: the upper screw is not as bad as it looks because the secondary hole didn't affect where the screw bites into the frame. I did a little cosmetic work here with super glue. The bottom screw was a different story. The secondary hole intersected the wall of the primary screw hole. This is why the bottom screw didn't feel tight. I made a plug for the secondary hole from a plastic/nylon spot tie and glued it in place. After the glue set, I trimmed the plug down and used the screw to "thread" the plug. Time will tell, but I was able to repeatedly snug the side plate screws firmly in place.




      The happy ending?....with the new cam in place and everything back together, I've put about 125 rounds downrange without a single light strike

      Regards,
      Greg
      sigpic

      Comment


      • #4
        That's impressive what you have done to make your p380 function correctly. From the diagnosis down to the obstacle impaired fix. You are great at fixing what I wound not even consider attempting. Everyone with a p380 problem should send their gun to you instead of Kahr. It would be fixed the 1st time.

        Comment


        • #5
          Well done and with pictures told the whole story.

          Comment


          • #6
            A used P380: the good, the bad, the ugly, and a happy ending.

            In addition to awe inspiring expertise and ingenuity, there's also a mystery. Why was the new cocking cam so different?

            I heard that a certain run of P380s made around 2010 had light strike and other problems. Serial numbers RB and early RC. I thought the issue was the frame but wonder if the new cam design is part of a change Kahr made in response?
            Rest in peace Muggsy

            "Individual Muslims may show splendid qualities, but the influence of the religion paralyses the social development of those who follow it. No stronger retrograde force exists in the world." Winston Churchill 1899

            Comment


            • #7
              Wow! Very impressive. Where did you get all the knowledge and confidence to do all that work on your Kahr?
              "I hate quotations. Tell me what you know."
              Ralph Waldo Emerson

              Comment


              • #8
                I wonder how many KahrTalk members have the mechanical aptitude, the troubleshooting skills, and the perseverance displayed by Greg in this thread?

                So, the next time a newbie posts about their frustration with a new gun they expected would function correctly, out-of-the-box, I hope the Kahr disciples remember Greg's experience. Their frustration may be justified.

                Well done, Greg!
                NRA Life Member

                "Owning a handgun doesn't make you armed any more than owning a guitar makes you a musician." -Col Jeff Cooper

                Comment


                • #9
                  What kind of glue did you use in the frame when gluing the zip tie in place?
                  Comparison is the thief of Joy....

                  CW380
                  MK9

                  Comment


                  • #10
                    Just out of curiosity I disassembled my P380 to see which cocking cam is in mine. The gun had the frame replaced by Kahr about six months ago. It has the new style of cocking cam. I guess we now know what to tell someone who is experiencing light strikes. Send your gun to Greg.
                    Never trust anyone who doesn't trust you to own a gun.

                    Life Member - NRA
                    Colt Gold Cup 70 series
                    Colt Woodsman
                    Ruger Mark III .22-45
                    Kahr CM9
                    Kahr P380

                    Comment


                    • #11
                      Originally posted by gb6491 View Post



                      Nicely done, sir!
                      It would be so nice if something made sense for a change.
                      -- Alice in Lewis Carroll's Alice's Adventures in Wonderland

                      Comment


                      • #12
                        Folks,
                        Thanks for all the comments, I very much appreciate you taking the time to do that

                        To answer a few questions
                        Originally posted by SlowBurn View Post
                        In addition to awe inspiring expertise and ingenuity, there's also a mystery. Why was the new cocking cam so different?

                        I heard that a certain run of P380s made around 2010 had light strike and other problems. Serial numbers RB and early RC. I thought the issue was the frame but wonder if the new cam design is part of a change Kahr made in response?
                        Originally posted by muggsy View Post
                        Just out of curiosity I disassembled my P380 to see which cocking cam is in mine. The gun had the frame replaced by Kahr about six months ago. It has the new style of cocking cam. I guess we now know what to tell someone who is experiencing light strikes. Send your gun to Greg.
                        This is an "RB" serial number range P380, thanks for bringing that up SlowBurn.
                        As muggsy has checked his P380 with a new frame (thanks for that!) and found the new style cocking cam, I suspect Kahr has tweaked the frames to add more polymer in that area.

                        Originally posted by Bill K View Post
                        Wow! Very impressive. Where did you get all the knowledge and confidence to do all that work on your Kahr?
                        I've a lot to learn, but I've always been a tinkerer, the rest I blame on the Marine Corps (noting your 542 Tigers patch, I imagine you can relate to that, Semper Fi Brother).

                        Originally posted by ReManG View Post
                        What kind of glue did you use in the frame when gluing the zip tie in place?
                        Super glue. It seems to hold it pretty well as I installed and removed the side plate quite a few times to test it (outside a parts failureI don't foresee taking it off again). There are probably some mechanical considerations as well: the shape of the plug helps keep it from turning, pressing the plate down while installing the screw prevents it from lifting, and there's pressure on it from the screw once it's installed.

                        Regards,
                        Greg
                        sigpic

                        Comment


                        • #13
                          Ditto what everyone has said about your analysis and mechanical abilities. You make a helluva gunsmith! Thanks for all the neat pictures!
                          Life member - NRA
                          Life member - CA Rifle & Pistol Assn.
                          SW desert rat

                          Comment


                          • #14
                            Greg is one incredibly smart cookie. Very mechanically talented. Definitely my #1 go to guy when I'm trying to figure something out.

                            If I took my gun down that far it would probably never look like a gun again and certainly never work properly.

                            My hats off to him as usual. Very well done.
                            http://bawanna45.wix.com/bawannas-grip-emporium#!
                            In Memory of Paul "Dietrich" Stines.
                            Dad: Say something nice to your cousin Shirley
                            Dietrich: For a fat girl you sure don't sweat much.
                            Cue sound of Head slap.

                            RIP Muggsy & TMan

                            Comment


                            • #15
                              Excellent work Greg! Nice pics as well. I think you know this, but like Col B said above you are also my #1 go to source for intelligent and detailed info. When I start digging into an issue I always check to see if you have already dealt with it or something similar, and most times you have, and that saves me a lot of time in doing my own mods.

                              Comment

                              Working...
                              X