CM40 Problems

[jmtaylo3]

I just purchased a CM40 because I carry a H&K USP 40 Compact and wanted to have a backup pistol that was also.40 Cal. I’m very disappointed in the unreliably of the CM40 as a defense weapon so far…many problems!
1) After 10 cleanings, I have bent two slide stop springs, one supplied by Kaur under warranty. Slide stop becomes stuck during the disassembly process and sometimes won’t reseat properly after reassembly, resulting in the slide becoming restricted in movement as I rack the slide back and forth. I’m following the instructions supplied (I have a P9, with similar spring…never had any problems.

2) After 150 rounds, break in period, I’m using a high quality Federal, hollow point, defense ammo that after about 12 shots, next round will not chamber properly and gets stuck between the magazine and the barrel…not quite a “stove pipe”…Kaur’s solution is to keep trying out different brands of ammo.

3) Slide extractor really gouges the ammo during the extraction process.

I’m in the process of sending the gun back to Kaur, but they have been reluctant to offer any advice or comments on what the problems could be, brand of ammo I should use, offered very little advice, and felt I should allow the problems to work themselves out by using even more ammo. I never had such problems with a pistol “right out of the box” before, and now am wonder if I made a big mistake in purchasing this thing. It shoots well and recoil is easy to control , but would be hesitant to use it as a defense weapon. I found your website, and would appreciate any suggestions.

[100percent]

Sounds like my 8 year old PM 40. The extractor was polished and problem went away.
http://veloliner.com/smallgun/pm40extractor.JPG

I have gotten good as stripping the slide down.
It should work out of the box.

[jmtaylo3]

Thanks,
sounds like a good solution I can recommend to Kaur. I'm not sure I want to start tinkering with a brand new gun. What type ammo do you suggest? So far onlycheap PPU made in Serbia works. Federal 180 grain and Speer Gold Dot165 grain have multiple hang ups

[pbagley]

Sorry to hear of your problems. I just bought a CM40 as well (posted my first range visit report in this forum) and had no problems with Winchester White Box 165gr FMJ's other than one fail to feed at round 42 that sounded a lot like yours (round still in the magazine, nose against the feed ramp, slide nearly all the way back). I blame myself for a limp wrist on that shot.

My brass was not damaged by the extractor - I just sized the 100 cases I shot last Wednesday this morning. In that lot was one extra Winchester case I found on the range and it had a thicker rim than the 100 that I shot. Is it possible that your ammo is within tolerance but the rim is on the thick end? Then there is the extractor being a little sharp on the edges. I have a CW45 that tears up case rims pretty badly and I think I'll be following Mr 100percent's example of polishing the extractor and rounding the sharp edges.

The bent slide stop springs are a concern. I've got three Kahr's and have had no issues in this area. It sounds like something is a little out of spec. Post some photos and someone on the forum may have some advice. There are a lot of experienced people on the forum, and most are very helpful.

[100percent]

I can't answer your question well as I don't shoot factory ammo. Usually it is Lead bullets that I cast. I have found that the overall length is critical, with my bullet, that length is 1.13" Shorter and longer are bad. Perhaps you can measure the OAL

The good news is that you seem to have found ammo that your gun shoots. Nothing wrong with shooting ball ammo.

[jmtaylo3]

the Ammo that seems to be working is a hollow point..ball ammo wouldn't work either. The type I was trying to use is "top of the line" defense ammo...I will try and post some photos later. I like your idea on polishing the extractor.


_______________
"if someone has a gun and is trying to kill you, I wouldn't trust this one to shoot back with"


I guess I need to send it back to Kaur.

[jmtaylo3]

can't figure out how to post a photo yet

[jmtaylo3]

I'm a "junior Member" so I'm not allowed...sigh. How did you polish your extractor 100percent? Kaur hasn't sent me instructions yet on a pre-approved return for service yet.

[pbagley]

I use http://www.servimg.com for posting photos. Free. Just include the the BBcode image link in the body of your post.

Here is an example:
http://i57.servimg.com/u/f57/13/62/95/74/20140421.jpg (http://www.servimg.com/image_preview.php?i=668&u=13629574)

[jmtaylo3]

being a junior member prevents me from posting the photos. I just sent the pistol back to Kahr..I hope they can adjust it so it's reliable!

[SDGlock23]

No you can post photos, you just have to use an off site service. Upload the pics to whichever service you choose (like Imgur for instance), then copy the link for the picture and past the link here.

Sorry to hear about your CM40. Mine runs great, but I do have to use a very tight grip on the thing or else sometimes it won't feed. I did polish my slide internals way back and I've never had the issue you're describing on the CM40, but I did on my new CW380 and it was the ammuntions fault, too much belling left in the case.

Make sure to lube your CM40 liberally and hand rack the slide a bunch too, a whole lot really.

[garyb]

No you can post photos, you just have to use an off site service. Upload the pics to whichever service you choose (like Imgur for instance), then copy the link for the picture and past the link here.

Sorry to hear about your CM40. Mine runs great, but I do have to use a very tight grip on the thing or else sometimes it won't feed. I did polish my slide internals way back and I've never had the issue you're describing on the CM40, but I did on my new CW380 and it was the ammuntions fault, too much belling left in the case.

Make sure to lube your CM40 liberally and hand rack the slide a bunch too, a whole lot really.


Yep....rack the crap out of it. Break it in.

[jmtaylo3]

I sent the gun back to Kahr for repair. Hopefully it will come back in working condition. I did rack the slide several hundred times before use as recommended by this website. I also have downloaded the 10 recommended lube points on the Kahr pistol ...there are 2 points that I have missed. They are not indicated in the instructions provided by Kahr. Cheap Walmart PPU ammo works just fine...good quality Federal and Speer Gold Dot don't work at all.