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View Full Version : CM9 night sight keeps breaking


Russ
10-13-2011, 07:54 PM
Had Kahr install night sights and the front sight has broken off twice. Has anyone had the same problem and what did you do? Kahr is stumped as to why they keep breaking in less than 100 rounds. Sorry I can't remember the spelling but begins with the letter T.
bonjorno2
10-13-2011, 08:22 PM
trijicon? I've had 0 issues with my front sight makes me worry when I shoot it because this is becoming more common.
gb6491
10-13-2011, 08:27 PM
Russ,
I don't have a CM9, but I have installed the Trijicon sight on my CW45 and CW9: both pistols have beaucoup rounds down range since then with nary a sight issue other than holster wear. I would have to think that there is either a run of defective sights or they are being installed incorrectly. Are you seeing any damage/wear marks on the sight or screw? Is the post snapping off at the base? Exactly how is the sight failing? Could you post a photo of the failed sight?
Regards,
Greg
Benaiah
10-13-2011, 08:45 PM
Where does it break?
Russ
10-13-2011, 09:53 PM
The first the sight got loose and at about 80 rounds it flew off. The second the screw snapped off clean flush with the top of the slide at 48 rounds. Trijicon is the name thanks. Kahr asked if there was any wear marks on the gun barrel. I couldn't see anything. I sent the entire gun back this time. I am hopping they fire multiple rounds. They assured me they used loctight both times. The.barrel or chamber I think has got to be hitting the screw for it to break off in 48 rounds. They have been sitting on this gun for two weeks.
gb6491
10-14-2011, 07:38 AM
The first the sight got loose and at about 80 rounds it flew off. The second the screw snapped off clean flush with the top of the slide at 48 rounds. Trijicon is the name thanks. Kahr asked if there was any wear marks on the gun barrel. I couldn't see anything. I sent the entire gun back this time. I am hopping they fire multiple rounds. They assured me they used loctight both times. The.barrel or chamber I think has got to be hitting the screw for it to break off in 48 rounds. They have been sitting on this gun for two weeks.
Well the first one certainly seems to be a case of improper installation. The second could be a faulty sight (which I doubt as I only found one other member having a broken sight {admittedly quick search}) or improper installation. I'm guessing that the screw was either over torqued or the head of it was not flush with (or below) the surface of the slide. I did a diagram sometime back about how I feel the sight needs to be fitted and installed. If you look at you can see what I mean about the head of the screw. You won't be able to check some of the other areas as Kahr is doing the installation, but I would definitely check how that screw head is installed when the gun is returned. It must not protrude above the surface of the slide. Here's the diagram: http://kahrtalk.com/showpost.php?p=90890&postcount=63
Regards,
Greg
Russ
10-14-2011, 07:48 AM
Greg

Impressive diagram. I have got to think Kahr is not getting the screw flush. This will be the third attempt by Kahr to get it right. I sent the entire gun back so hopefully they will fire several rounds. I am thinking maybe the slide screw hole is not allowing for the screen to seat properly. Very puzzling.
gb6491
10-14-2011, 07:55 AM
BTW Russ, didn't you have some issue with your slide hanging up?
If that screw head is not flush it can interfere with the slide going into battery. This was reported by several folks with CW9s when the sights first became available. During the initial part of install on my CW9, the head protruded enough that the barrel could not even be installed: http://kahrtalk.com/showpost.php?p=54961&postcount=27
Regards,
Greg
Benaiah
10-14-2011, 04:58 PM
It seems like there would be a witness mark on the top of the barrel if the screw was sticking out of the countersunk hole. Am I thinking correctly?
gb6491
10-14-2011, 07:16 PM
It seems like there would be a witness mark on the top of the barrel if the screw was sticking out of the countersunk hole. Am I thinking correctly?
Yes, there probably will be "witness" mark(s) on the barrel if the screw was sticking out. The problem is the mark(s) might not be readily apparent; possibly appearing as little more than a polished spot on the barrel (I have seen this). The slide also burnishes the barrel in that area leaving some portions shinier than others, so another spot near by might seem to be part of that evolution
Regards,
Greg
stumprat
10-14-2011, 07:33 PM
I recieved my front sight in the mail last friday. Installed using RED loc-tite and let it cure for 24 hours.
I have since put 250 rounds through it and got it quite hot to test out the installation.

So far, so good.
les strat
10-14-2011, 08:22 PM
Mine has had about 200 through it since installation. No trouble here. I am betting it is an installation thing.
BEARDOG
10-14-2011, 09:02 PM
Me three! My CM9 has been fired about 200 rds also with the new Trijicon front, and was pretty hot too. NO problems.

It's funny the only 2 cases (I know of) of this happening are when Kahr service or a gunsmith installed them???
Seems the rest of us "normal guy's" can handle 1 screw and some loctite LOL.
Russ
10-14-2011, 09:36 PM
Greg

The slide was hanging up before I had the sights changed out.

Had a chat today with the area sales rep. He covers my State Utah. He responded to an email I sent him last night. He is really down on changing out the pin sights on the CM9. I am getting to that point. I can see the dove tail sight on the PM9 may be a better setup.