CM9 front sight issues

[Shuz]

I've had to send my slide back to the factory twice now to have the front sight replaced. Both times, the front sight flew off and is in "orbit" somewhere down at my range! The sights on my CM9 are the "night sights". Have any others had this problem? The gun has never seen plus P loads.

thanks, Shuz

[Alfonse]

In my experience that is usually due to one of these things:

* not using thread locker on both the screw threads and the base of the sight. It should squeeze out all around the sight as the screw is snugged up.

* all lubricant needs to be off the slide and sight for the thread locker to bond. Many solvents, like Hoppes #9, leave a "protective film" which is actually oil. Use something like Gunscrubber that is solvent only.

* the screw is over tightened. Tightening the screw too much won't help the sight stay on. The screws are small and should only have a few inch pounds of torque on them at most. Over torquing them damages the threads on the screw and/or sight and off it will come.

Just my $.02

[bugs]

IMHO, a dovetail for the front sight is needed; I had LGS do mine. no worries about breaking ft. sight off, more sight options available to you.

NRA LIFER

IDPA BELEIVER

[Shuz]

Alfonse--I bought the gun new with the night sight option. All I did was fire the gun about 10 or 12 times and the front sight flew off.
I contacted the factory and they told me to send the slide back to them. I did just that, and when I got the slide back I installed it in the gun, fired it a few times and put it away for some time. When I got the gun out again this past week I fired about 10 rounds and the front sight flew off again. The factory guy said that shouldn't happen and said to send the slide back again. I did that and asked in the letter if they wouldn't dovetail my front sight in. I was just wondering if any other CM9 users have had the same issue as me.

[gb6491]

In my experience that is usually due to one of these things:

* not using thread locker on both the screw threads and the base of the sight. It should squeeze out all around the sight as the screw is snugged up.

* all lubricant needs to be off the slide and sight for the thread locker to bond. Many solvents, like Hoppes #9, leave a "protective film" which is actually oil. Use something like Gunscrubber that is solvent only.

* the screw is over tightened. Tightening the screw too much won't help the sight stay on. The screws are small and should only have a few inch pounds of torque on them at most. Over torquing them damages the threads on the screw and/or sight and off it will come.

Just my $.02

I totally agree with this. I think folks (to include the factory folks) are too quick to put the sights on the slide and just snug them down nice and tight. I've found that the Trijicon front sight and the pistol's slide require some fitting for proper sight installation. Here's a post I made sometime back in regards to this:

Seeing as how there are variances in how slides are countersunk for the front sight posts on "C" (and "E") series guns, I thought I'd put up some diagrams in regards to what I've found is involved with "fitting" the Trijicon front night sight. YMMV.
First, do a dry run installation.
Check that the sight will fit flush on the slide. Then check the posts for correct clearance on the inside of the slide. Finally, install the screw and check that it holds the sight flush to the slide and fits correctly into the countersink.


*note - in the diagrams, fit of the sight posts in their holes and screw head in the countersink are exaggerated to show the parts clearly. The posts fit closely in real life and the screw head will be in contact with the sides/bottom of the countersink.

Once satisfied that the fit is correct, install using an adequate amount of red Loctite.

Post #27 contains instruction for removing the factory front sight and installing the Trijicon sight (some mention in post #1 as well).

Regards,
Greg

I've installed the Trijicon front sight in this manner on a CW45, CW9, and CM9 and not had an issue with any of them.

Regards,
Greg

[Ed M]

Some time back, I replaced the front sight on my CM9 with the Trijicon night sight.

My front sight flew off as well after some range time.

I called Kahr, and they said they had some problems with this happening, and they had Trijicon thread both posts, and included 2 screws with the sight kits.

I would still do what Alfonse and Gary do when installing a front sight of this design, but the 2 screw setup seems pretty secure.

I've since done another front sight install on my CW45, and this one worked out well too.

[Shuz]

I would think that the folks at Kahr would do well to look at the diagram that gb6491 posted. Can any of you folks who are computer savey send this to them?
thanks,
Shuz

[Bigdave35180]

Greg...what is the distance between posts c-t-c if you know...

[Shuz]

The slide has been rec'd back at the factory. Now I wait to see how long it will take to "factory fix" my issue.

[Alfonse]

The slide has been rec'd back at the factory. Now I wait to see how long it will take to "factory fix" my issue.

Hopefully they will get it back to you quickly and mounted securely. Greg is also correct (which is pretty much redundant), if the fitting is off that can cause it to come off too. The design can work really well (in fact, it can be more difficult than one would think to get them off sometimes).