CM40 weird hitch when manually pulling slide

[pyrobooster]

Hello all,
New member here and new to Kahrs.
The CM40 just outside of the break in period, and Im noticing an odd "hitch" as the slide is manually pulled back with an empty magazine in.

It happens about when the slide reaches the point of the barrel fully recoiled and the slide is just separating from the barrel as it goes back and forth too. The odd thing is that it does not happen when the magazine is out.

Could this be a symptom of the ramp impacting the follower and not making it all the way back or something else?

Thanks guys!

[gb6491]

Hello all,
New member here and new to Kahrs.
The CM40 just outside of the break in period, and Im noticing an odd "hitch" as the slide is manually pulled back with an empty magazine in.

It happens about when the slide reaches the point of the barrel fully recoiled and the slide is just separating from the barrel as it goes back and forth too. The odd thing is that it does not happen when the magazine is out.

Could this be a symptom of the ramp impacting the follower and not making it all the way back or something else?

Thanks guys!
My first thought is that what you describe may be caused by the slide stop.

With an empty magazine in place, the magazine follower is lifting the slide stop lever so that it interfaces with the notches on the slide (stop notch and disassembly notch).

With the slide at the position you mention, I'm guessing what you feel is the disassembly notch riding over the slide stop lever. The stop lever will lift some, though not engage when that happens, but it could account for the little hitch you feel.

As a quick test, with the empty mag installed, hold the stop lever down a bit as you work the slide.

Regards,
Greg

[pyrobooster]

Greg,

Thank you very much I really appreciate the suggestion. I will try that out asap. From the top of my head it seems that is about the point the "hitch" was happening.

This forum and its great members are great help to the Kahr Community.

Thanks again! - pyrobooster

[pyrobooster]

Greg,

I can still feel the "hitch" even when holding the slide release down. Is it possible some thing else is impacting or scraping the the follower? Or could this be the barrel touching the front of the follower and not making it all the way back by a tiny margin and the slide is rubbing that?

Thank you in advance,
pyrobooster

[gb6491]

Greg,

I can still feel the "hitch" even when holding the slide release down. Is it possible some thing else is impacting or scraping the the follower? Or could this be the barrel touching the front of the follower and not making it all the way back by a tiny margin and the slide is rubbing that?

Thank you in advance,
pyrobooster
I suppose the center rail of the slide could be dragging on the follower or some part of the slide is catching on the top of the magazine.
You might check the follower and the slide for any telltale marks.

I also wouldn't discount your question about the ramp bumping the follower.
You could probably check this by removing the top end and reinstalling just the barrel and slide stop in the frame, then install an empty mag and press the barrel down and rearward while checking for contact.

Regards,
Greg

[Ed M]

First thing that came to mind when I read this was maybe you're getting some barrel peening.

It's not unheard of in Kahrs.

Might want to check your barrel hood, and where it contacts the slide.

Here's a pic I downloaded from google....

http://www.kahrtalk.com/attachment.php?attachmentid=15198&stc=1

[pyrobooster]

I suppose the center rail of the slide could be dragging on the follower or some part of the slide is catching on the top of the magazine.
You might check the follower and the slide for any telltale marks.

I also wouldn't discount your question about the ramp bumping the follower.
You could probably check this by removing the top end and reinstalling just the barrel and slide stop in the frame, then install an empty mag and press the barrel down and rearward while checking for contact.

Regards,
Greg

Greg, thank you very much for your suggestion and idea I will try that right away.

[pyrobooster]

First thing that came to mind when I read this was maybe you're getting some barrel peening.

It's not unheard of in Kahrs.

Might want to check your barrel hood, and where it contacts the slide.

Here's a pic I downloaded from google....

http://www.kahrtalk.com/attachment.php?attachmentid=15198&stc=1

Ed M , the slide definitely rubs over the barrel but it does not appear to be "impacting" rather rubbing. What else might I look for in the case of peening ?
Thank Ed!

[Ed M]

Rubbing is normal.

When the edge of the hood on the top or sides starts to raise up from impact, it's not normal.

Just google "Kahr barrel peening images" and you'll see more. There will also be a corresponding damage area on the slide.

More rounds through the gun will reveal the problem - if there is one.

[pyrobooster]

Rubbing is normal.

When the edge of the hood on the top or sides starts to raise up from impact, it's not normal.

Just google "Kahr barrel peening images" and you'll see more. There will also be a corresponding damage area on the slide.

More rounds through the gun will reveal the problem - if there is one.

Hey guys, so I looked around and do not have reason to believe peening is an issue at this point.

The "hitch" still remains.

It ran flawlessly last time except it would FTF when taking only the first round off the top of a fully loaded 6 round mag in a 6+1 scenario. If I do 5+1 (in the 6 round mag) runs flawless or 7+1 in the 7 round mag no problems. Seems only in a 6+1 is there a problem.

The waters are getting murky on this but does that tell you anything about the possible cause of the "hitch" ?

Thank you again your knowledge is much appreciated.

[AnthonyC]

I had a similar problem with my CM9 and it turned out to be the nut on the end of the recoil spring/guide rod assembly. It would hit the edge of the opening at the muzzle end of the slide when racked. Try looking at that when you rack it (gun unloaded, of course) you might see that nut catching and feel a hitch in the movement.
Good luck.

[pyrobooster]

Thanks for the heads up. Kahr sent a free recoil spring that has almost fixed the issue. It feeds better and does not have the "hitch" anymore. I'm thinking one of the extra strength recoil springs from Wolf might help even more. Thank you

[Ed M]

I'm thinking one of the extra strength recoil springs from Wolf might help even more.

You may want to call Wolff on this one.

The regular strength recoil springs are 13 coil springs - they fit the older style PM9 with the blunt nose.

I haven't bought any of the extra strength recoil springs, and don't know if they're 13 coil or 15 coil.

The CM9 takes a 15 coil spring, so you might not be gaining anything if the extra strength spring is a 13 coil one....

[Bawanna]

This is a 180, usually people are concerned that the springs are too stiff.

The factory springs are also supplied by Wolff so as Ed mentioned, contacting them might be a good idea.

[pyrobooster]

Good advice, I will do that thank you!


You may want to call Wolff on this one.

The regular strength recoil springs are 13 coil springs - they fit the older style PM9 with the blunt nose.

I haven't bought any of the extra strength recoil springs, and don't know if they're 13 coil or 15 coil.

The CM9 takes a 15 coil spring, so you might not be gaining anything if the extra strength spring is a 13 coil one....

[pyrobooster]

Thanks for weighing in, I appreciate it. I will do that for sure.


This is a 180, usually people are concerned that the springs are too stiff.

The factory springs are also supplied by Wolff so as Ed mentioned, contacting them might be a good idea.