New CM9 Showing Marks on Left Side of Slide After 50 rds

[alltimeqb]

Thanks to all for the input. I guess Kahr feels this is ok. I'll go ahead and take the top off that slide stop that is so close to the slide.

[jimrod1969]

Here is a pic of my modified CM40 slide stop that de-horns/ removes the sharp edge that cause the gouges in your slide. The slide stop in the foreground is the modified one and the one behind is an is an unmodified stock part. Note the removal of the sharp edge and general polishing in the area of where the cross-pin mates with the slide stop. That sharp edge is the culprit. On my CM9, I have no problems as there is just enough clearance between it and the lower edge of the slide that no contact results during firing. On my CM40, the clearance was much tighter and I suspect under firing, the frame flexes and causes hard contact. Now there is sufficient gap/ clearance that there is no more contact and no further marks on my slide. I did this to my CM9 and CW380 stops as well just to make sure that no issues crop up with those. I did all three in about an hour. All is needed is a vice, a small flat metal file (I used coarse double bastard cut), a sharpening/ polishing stone, and sharpening stone oil. Put the stop in a vice and SLOWLY work down the sharp edge with the file while carefully avoiding contacting other parts of the stop and scratching up the finish where you don't want to. Use sharpening oil throughout the process. Reshape the sharp edge to make it rounded and take it down enough to provide maximum clearance with he slide. When your happy with the shape, use the square edge of a fine sharpening stone with oil to polish the surfaces smooth, removing any burs. That's it! There is no loss in structural integrity with this mod and Kahr should have incorporated this relief into their casting tool (too bad we have to become home gunsmiths). Hope this helps.

[alltimeqb]

Thanks jimrod. The picture of what you've done is very helpful. Kahr did say they would send a new slidestop, but, as others have alluded to, Kahr considers this normal due to their tight tolerances. I'll take the edge off those marks in a few days.

BTW, anyone who has experienced the marks have a picture of the results of trying to knock 'em down?

[jimrod1969]

I'll take the edge off those marks in a few days.

BTW, anyone who has experienced the marks have a picture of the results of trying to knock 'em down?

I haven't done anything to the marks on the slide. I would be interested to learn about what you will do and see the pictures after it's done.

btw, that second unmodified slide stop in my pic is the one Kahr sent me. If I install it in my particular gun the slide gouging will continue...just the stack up of tolerances on my gun. Better to take the edge of the stop before your slide gets worse IMO. Good luck To!

[alltimeqb]

I did get the new slide stop and you are absolutely correct; I need to file off that edge before I go put even 1 more round through it! I'm probably not going to touch the slide anytime soon, but when I do, I'll post a pic.

[jimrod1969]

Good luck!

[alltimeqb]

Just to put the last nail in this coffin ;-)

Kahr sent me a new slidestop. After installation, it was apparent that the original part was at the upper end of the tolerance range (don't have explicit measurements nor do I have Kahr's design intent for dimensional tolerance of the part so I cannot objectively state that it was outside of tolerance), but the new slidestop looks to have no problem relative to the proximity of the slide itself. I looked at the original slidestop... right at the top edge closest to the slide, the corner is worn. This is exactly what caused the marks on the slide (like we didn't know), but I really cannot believe that Kahr is satisfied to just say; "don't worry about it, it's because of the close tolerances of a new gun, it doesn't effect performance..."

That is not the response of a company who is proud of their product. The new slidestop I received in the mail is clearly made within a different tolerance range as I didn't even need to file it down to see that it won't mark the slide.

After 50 rounds, I think I'm glad I purchased this gun, but I doubt I'll be purchasing another Kahr product anytime soon because I'm not that confident in their commitment to building a quality product. Some may think it's not that fair to make a judgement like this after a one product purchase, but I've bought Rugers, Smiths, Mossbergs, Remingtons, Springfields, Winchesters, AMTs and some others I'm forgetting about and have never had an issue with any one of them.

I'm sure there will be those who flame me, but at the end of the day that's my honest opinion.