yet another cm9 range report...

[kahrl]

after experiencing various malfunctions, and executing numerous "improvements" and modifications (polished feed ramp, shortened feed ramp, refined mag follower), i really thought i had it nailed. i could slingshot, even get lazy with it, and it functioned perfectly. at the range on saturday, i ran about a hundred rounds through it, for a total of about 250. suddenly, depression set in. failure to reset. i tried different ammo. same thing. i diddled with the trigger, and eventually it would reset. it was in full battery, but would not reset. there is no way i'll carry this thing. too unreliable. any ideas as to what may be causing this problem? i tried to replicate it at home with dummy ammo, and was unable to recreate the condition.

[stuch77]

i got an idea. you got a bad one send it back to kahr.

[kahrl]

i got an idea. you got a bad one send it back to kahr.
yup. and maybe get a ruger lcr while i'm waiting... ?

[Alfonse]

yup. and maybe get a ruger lcr while i'm waiting... ?


Whatever.

[addictedhealer]

yup. and maybe get a ruger lcr while i'm waiting... ?

Send it in, but don't give up on it. Sorry for your bad luck, but with any mass produced item there will always be f ups. I have a LCR and love it. Like my Kahr better, but the LCR is a great gun with yet again another great trigger.

[scosgt]

Did you ever take down the slide and clean it out? FP or safety could be sticking.

[kahrl]

Did you ever take down the slide and clean it out? FP or safety could be sticking.
i haven't torn the slide down, but i probably will. i did a light cleanup when i got home, and the problem "went away". i did see some tiny brass flakes floating around in there. i haven't shot cleaner into the slide hole since the last range episode. i'll do that and see if i get anything. i've been manually racking the slide just enough to clear the reset (with the trigger pulled), and then release the trigger to reset, and it is getting smoother. my trigger was very jerky on return initially.

[kahrl]

Whatever.
it's settled, then. thanks. :)

[scosgt]

i haven't torn the slide down, but i probably will. i did a light cleanup when i got home, and the problem "went away". i did see some tiny brass flakes floating around in there. i haven't shot cleaner into the slide hole since the last range episode. i'll do that and see if i get anything. i've been manually racking the slide just enough to clear the reset (with the trigger pulled), and then release the trigger to reset, and it is getting smoother. my trigger was very jerky on return initially.

Take it apart and clean it all out, I think all the parts in the slide need to line up for the trigger to reset. I could be wrong, but if it is really full of carbon and oil you should clean it up and try at the range again. Sometimes it is something stupid.

[scosgt]

I actually went down and took mine apart. This would be a fatal failure in a gunfight, so I have some concern.
There are only two things I can see that would cause a failure to reset:

The trigger has two "nubs". When you pull the trigger, the center nub is the sear that releases the striker. The other nub presses the FPS. You get a reset when the Striker spring is captured by the center nub and the trigger is all the way forward, which means the nub has rotated into the cutout in the striker.

So, the possible failures:

The nub is not anchored properly and does not rotate into the notch OR is broken or misshappen and does not grab.

OR

The notch is broken or misshapen and does not allow the nub to rotate in.

The other possibility, looking at the mechanism, is that there is a problem with the striker spring which is not allowing the striker to be pulled all the way to the rear where it engages the nub into a reset.

So, check that the nubs are solidly attached and not damaged. You should not be able to prevent rotation by holding one of them.

Check the plastic striker spring plunger is not deformed or burred. This would prevent the spring from compressing completely.

Make sure that there is not something in the striker channel (brass, solid carbon) that prevents the striker from going all the way into reset mode.

Mechanically, these appear the be the only things involved in a trigger reset, so the answer has to lie there. My biggest suspect would be the spring and plastic plunger. If the striker can not withdraw all the way to the rear smoothly, you will not get a reset.

[scosgt]

One other thing to look at. When the trigger is held to the rear, the flat end of the center nub captures the striker and pulls it to the rear. If that piece is broken or out of position, it will not grab the striker and you can never get a reset since the striker is forward. If that was the case, you MIGHT get slam fires as the firing pin will be protruding. However, the force of hitting a primer might just drive the pin back since there is almost no spring tension at that point.
If it happens again, what you would want to do is drop the magazine, remember you have a live round in the chamber, and carefully, with the muzzle pointed downrange, pull the the slide and try to see the position of the strike spring. If it is not compressed, it is not being captured at all on recoil. Just pull back a bit and turn it upside down or sideways so you can see the spring. That would narrow it down if you can not find a cause as suggested above.

[scosgt]

AND, I also wonder if the frame can be flexing or warped enough to prevent the striker from being captured. There is not much meat in there. You would not be able to duplicate that without firing, the recoil could be making the gap too big for the nub to grab and retract the striker.

[kahrl]

AND, I also wonder if the frame can be flexing or warped enough to prevent the striker from being captured. There is not much meat in there. You would not be able to duplicate that without firing, the recoil could be making the gap too big for the nub to grab and retract the striker.
thanks for the input, scosgt!! i will be checking all of the above. i should have time this weekend to tear it down.