Trigger Reset Fail

[yqtszhj]

Stick with the non-chlorinated brake cleaner or gun scrubber. You want something that will dry and leave no residue.

Use what AH said. Its jocko approved.

[seed]

http://www.kahrtalk.com/showthread.p...=failure+reset

The above thread is a good read for what probably accounts for this type of failure in many, if not most instances in polymer framed Kahrs. However, I encountered the problem with my MK40, which is steel framed of course. Upon careful examination, I observed that I could recreate the malfunction by not pushing down the tab hard enough...both with the slide removed and with the pistol fully assembled. In the former situation, holding the trigger all the way back, I use my finger nail to push down the tab (and trigger bar) just enough to have it clear the slide (if it was still on), but not enough to trip the dual cam sear/safety deactivator. With the slide still on, I could recreate the problem by deliberately racking the slide just hard enough to push down the tab/trigger bar to clear the slide, without enough force to make it reset the cam. In the latter case, it was much more difficult to cause the malfunction.

My conclusion is that the malfunction was caused by my grip panel screws loosening and allowing the trigger bar to bow, length wise outward, caused by the reset spring pulling it outward, without being blocked by a flush grip panel. This allowed the trigger bar to lean just enough to travel outward...enough to prevent full downward travel of the trigger bar during the cycling and resetting process. My solution is to use Loctite on the grip screws and perhaps get some stiffer grips to remove concern of any flexing or bowing of the superior/posterior portion of the grips themselves during firing (if this can happen at all as they heat up). It also doesn't hurt to keep grease away from the portion of the frame where the tab resides, as it could perhaps be sticky enough to sometimes prevent complete downward travel of the tab/trigger bar. I will test all this on my next range trip.

[Captrigney]

seed: Thank you for the instructional post. My cm9 is new with only 250 rounds through it so I don't see any wear or abnormalities in the areas in your post. However, I have found that I can re-create the malfunction if, with the slide attached, I pull the trigger all the way back and rack the slide while lifting/pulling the rear of the slide upward. It doesn't take much upward force to cause the reset failure. Can anyone else out there cause the malfunction with this method or is it a flaw in my cm9? Could this happen on live fire recoil?

After a closer inspection, perhaps there is some wear on the trigger bar tab. With my fingernail, I can feel that it is peened over some. It also looks like it is worn on the top half. Perhaps this is normal. More experienced eyes may be able to tell me. Here is a link to some photos (I've yet to accumulate enough posts to include photos in my posts).

https://www.dropbox.com/s/u7hs63xj4n...18.54.jpg?dl=0

https://www.dropbox.com/s/fq1t4qhx16...02128.jpg?dl=0

[seed]

Although in principle the problem is caused for the same reason in both metal and polymer framed Kahrs (incomplete downward travel of the trigger bar), there are differences in the likelihood and also the possibility of the cause...in polymer framed Kahrs, the tab can be trapped between the slide and frame rails, due to the flexibility of the polymer, whereas in steel framed Kahrs, the loosening of the grip screw (specifically the upper right grip screw) and or possibly some give of the plastic grip panel in the tab area (a thin, unsecured area) can cause an allowance for the trigger bar to tilt slightly, thus dissipating downward travel into some lateral travel. The problem is significantly more worrisome for the polymer framed Kahrs as it can be an inherent design flaw that could only be permanently prevented with a slight design change (i.e. perhaps some metal support in the frame for rigidity). With steel framed Kahrs, the problem is less frequent to begin with, is unlikely to damage the trigger bar tab and is perhaps easy enough to prevent with some owner precautions I outlined in my previous post. A design change may be possible by Kahr, but doing so would change the dynamics of the system and possibly make things worse before they get better. A possible change would be an ever so slightly heightened tab, but this could cause geometry problems down below where the dual cams interact with the trigger bar.

I am very interested in people's opinions here about it. Please tell me what you think.

[jocko]

I'd show them my ID and then take a good hit off the can before I left the counter. That would shake 'em up. You wouldn't believe how many times I've been thrown out of Walmart.

look at the money u save Muggsys. ur so high all the time and it cost u nadda. coure u could buy that air can and insert it where te sun doesnt shine and it might clear ur brain some to. Just sayin.

[jocko]

One reason ol jocko has recommended the non cholorinated brake cleaner, or any non cholorinated cleaner is that it is about 3 times cheaper than cleaners like gun scrubber that is the same thing only with alittle better perfume in it to make u feel good aobut getting fokked for paying that kind of money. IO any spray cleaner that drys fast is great for the striker chanel. I would say stay away form any lubing or any cleaners that leave an oil film. Keep the channel clean and dry, and that little clean out hole on the bottom front of the slide is just why it is there. It feed directly into the striker channel, so IMO every time u clean ur weapon give that channel a 5 second spray and ur good to go. I in over 32K rounds of my PMJ9 have had the striker channel down one time and that wasto insert the 5# striker spring and at that time I made sure that channel was perfectly clean and clear of any excess gunk left over at kahr. Since then I have used the hole every time I clean my weapon. The channel is supposed to be clean and free of crude when u buy it BUT we don't know that and we do know that many have cleaned and found crapola in there that hindered the striker somewhoat. Just errror on the side of caution.. Keeping poil as much as possable out of the kahrs actions will also keep ur pockets from staining to if u pocket carry. I just don't think u can be TW25 for a super grease on the kahr rails and slide groover. That little visible hump on the back of the triger bar by the right side frame, is a good place to put a dab of that grease to...Just sayin

[jocko]

Back on topic, I have to think it is user error (mine, of course) that caused the trigger reset fail. I was shooting groups a bit faster than normal so I may have short stroked the reset.

Back off topic: I'm new to strikers. Would Ballistol be a bad product to use in the striker clean-out hole because it is a CLP (L being Lube)? I've been using Break Free Powder Blast aerosol (I believe it is just a C with no L or P) followed by compressed air.

I can tellu that if u try to rapid fire a kahr, u better be damn good at giving that triger is due travel or u will get lite strikes. U GOTTA LET UP ON THAT TRIGGER.

[Captrigney]

I can tellu that if u try to rapid fire a kahr, u better be damn good at giving that triger is due travel or u will get lite strikes. U GOTTA LET UP ON THAT TRIGGER.

Rapid fire at my range is anything over 1 round per second. Faster than that and you get an intercom ass chewing. So, I wouldn't say I was rapid firing. I'll have another go at it next week and see what happens.

[seed]

seed: Thank you for the instructional post. My cm9 is new with only 250 rounds through it so I don't see any wear or abnormalities in the areas in your post. However, I have found that I can re-create the malfunction if, with the slide attached, I pull the trigger all the way back and rack the slide while lifting/pulling the rear of the slide upward. It doesn't take much upward force to cause the reset failure. Can anyone else out there cause the malfunction with this method or is it a flaw in my cm9? Could this happen on live fire recoil?

After a closer inspection, perhaps there is some wear on the trigger bar tab. With my fingernail, I can feel that it is peened over some. It also looks like it is worn on the top half. Perhaps this is normal. More experienced eyes may be able to tell me. Here is a link to some photos (I've yet to accumulate enough posts to include photos in my posts).

https://www.dropbox.com/s/u7hs63xj4n...18.54.jpg?dl=0

https://www.dropbox.com/s/fq1t4qhx16...02128.jpg?dl=0

I think those pictures show evidence of your Kahr experiencing the problem that Dorangolv detailed in his thread, possibly in addition to what you experienced with your testing...or perhaps a combination of the two at the same instance... Perhaps the tab is only slipping beneath the slide rail at the beginning phase of rearward motion, then freeing itself to be pushed down just far enough for clearance, but not enough for dual cam reset. This would explain the lack of total failures that Dorangolv experienced. Personally, I would notify Kahr that you need a new trigger bar and then follow Dorangolv's instructions on how to prevent the problem from starting all over again, damaging your new trigger bar. I feel very confident that you and I (and Dorangolv) have nailed down the cause of failures to reset for our Kahrs, as well as that of many, if not most others experiencing the problem. Good luck and let us know about your progress, as will I with my MK-40 with its related problem.

[Captrigney]

Here is a video of a trigger reset fail with the problem seeming to be that the trigger bar doesn't lift UP after racking rather than not getting pushed down enough: http://youtu.be/h5wFy81mQds

[Antarius]

Or take the trigger bar and bend it slightly upward so it's farther up in the first place?

[sas PM9]

Here is a video of a trigger reset fail with the problem seeming to be that the trigger bar doesn't lift UP after racking rather than not getting pushed down enough: http://youtu.be/h5wFy81mQds

Cap:

Thanks for that video. It helps explain what "his" gun was doing. And it looked to me like the trigger spring has weakened and is not providing enough upward motion in "his" case.
You can take off your side panel and see if the same thing is your problem too. If it is ( or even if it isn't) I would be inclined to call KAHR and request a RMA tag and let them fix it under warranty.

-steve

[Captrigney]

I emailed Jay at Kahr Support. I'll keep you posted.

[jocko]

Or take the trigger bar and bend it slightly upward so it's farther up in the first place?

that trigger bar is a b!tch to ever take out, I would advise against tht for sure If the bar is out of spec, then it needs to go back to kahr, end of story. If the owner fokks itr up thent he gun will come back maybe unfixed by kahr to. They will warranty their guns for this screw ups, not ours.

[Antarius]

that trigger bar is a b!tch to ever take out, I would advise against tht for sure If the bar is out of spec, then it needs to go back to kahr, end of story. If the owner fokks itr up thent he gun will come back maybe unfixed by kahr to. They will warranty their guns for this screw ups, not ours.

Good points.