CM9 - From Great to Awful to Great!

[Devo]

I am new here so I am sorry my first post is a plea for help. How did my Kahr CM9 experience go from great to awful?

First Range Trip

I took the CM9 to the range with only one goal. Put 200 rounds FMJ down range and break the pistol in. Using one six round magazine I put 200 rounds down range in two hours.

I must report one failure to feed at approximately round 180 loading the second round of a fresh magazine. Honestly after you have loaded 170+ rounds I could have just gotten careless and didn’t seat the round properly.
I honestly don’t know.

I cleared the jam and finished the 200 FMJ without issue.

I also ran a box of 9mm Winchester PDX1 +P without issue.

Never shot a PM9 so I can’t make the comparison. I can only say that I like this gun.

That’s my experience. No BS to make it sounds better than it really is.

Every visit since then..

All outings since I can’t run the six round magazine without a nose dive jam (round is wedged just below the feed ramp at a downward angle).

The nose dive jam always occurs on the second or third round.

Before I go on let me tell you the first round is chambered per Kahr specification. I also followed the prep instructions on this site.

I called Kahr to discuss the problem. I described it the same way as above. The Kahr representative asked if I was the first owner and my name and address (no serial number). He said they would send me a new recoil spring.
I had the opportunity to shoot the CM9 using a friends PM9 magazine. You see I initially thought the problem might be the magazine, but the CM9 jammed the same way with the PM9 magazine.

Is a recoil spring really going to address the problem?

[wyntrout]

I think this might be the magazine spring weakening. With the 9mm's, there's a tendency for the next cartridge to be dragged forward a bit as the first round is stripped off the mag and pushed forward. When you chamber a round, drop the magazine and see where the next round is situated. It's usually forward a bit, causing several possible problems. It can impact the slide lock actuator and cause premature slide lock, or the round can take a dive instead of going up the ramp.

I put stronger Wolff springs in my mags, but I still have those problems sometimes. I always drop the mag and top it off after loading the pistols for CCW, making sure that the top rounds are fully to the rear in the magazine. This should give you at least two shots before possible malfunctions.

I would get the largest capacity springs for Kahr from Wolff and use those.

Wynn

[ATF]

Devo,

You swapped magazines and the problem did not follow the magazine but rather stayed with the firearm. The PM9 and CM9 barrels are interchangeable. Swap barrels and see if the problem follows the barrel with the suspected issue with the feed ramp. If you get a jam on the PM9 that's your issue!

[Bawanna]

I find myself wondering what changed? Different ammo? Not cleaned. Not lubed or not lubed enough.

I'd make sure the feed ramp is clean and nice, the recoil spring certainly can't hurt but I doubt its gone bad unless it was weak to begin with and it worked fine for 200 so that theory is falling apart.

Something has changed and that's what we need to look for here.

[jocko]

devo, u gotta start somewhere, give the recoil springs a chance to prove yea or nay. Just very hard to tell what is causng this. Have you let ayone else shoot the gun to see if they can duplicate the same thing? Again u just need to eliminate all possable questions as to "why" I seriously doubt if it is magazine related, asyou tried different mags with the same results. Kinda odd that the gun can know when to act up on the xecond or thrid rou78nd and not any other rounds.. doucument all your efforts incase it has to go back so that the kahr tech people can start. wait or the spirngs and give it a try.

[Devo]

@jocko -
Agreed. Thanks for the advise on documentation.

@Bawanna -
The first time this occured was in the hands of my friend. He is now a PM9 owner and is the one who let me borrow his PM9 magazine for the CM9. The ammo on the succcessful range visit was Federal Champion found at any Walmat. Every range trip since has been a box of WWB and some 9mm reloads. Yeah I know reloads, but WWB behaved the same. I think it's a good idea to try the Federal again. I hope I don't find the Federal to be working. That would suggest I have a CM9 that is batting .333 on ammo. Good for the major leagure, but not what I am hoping for here.

@ATF -
I did not consider swapping the barrels. I am going to do that.

@wyntrout -
The problem didn't follow the mazagine, but round two in the CM9 magazine does "seem to me" like it lurches forward. Its not what I am used to when looking at my XD magazine.

[Bawanna]

I would definitely try the Federal again and see if it works. Then you can compare the two rounds the Federal and the WWB and see whats different. maybe the WWB is a little longer or the bullets shaped different.

This would also help the tech at Kahr if it gets to that point help pinpoint the problem. Handloads can be tweaked and fixed. At this point in your guns life I don't even take those into the equation.

Make it run on all factory ammo, then you can tweak reloads to work.

Usually WWB works well, never heard of guys having problems with it.

I agree with Jocko too, (his heads swelling as we speak) give the spring a try. I wouldn't waste any time switching barrels. I'd wager up to a quarter that ain't the issue. I'm going with different ammo.

[WilliamG]

The rounds definitely tend to move forward in the magazine, especially if you do a chamber check with a full magazine in there.

[Bawanna]

The rounds definitely tend to move forward in the magazine, especially if you do a chamber check with a full magazine in there.

Most all my auto's do that. Usually it doesn't hurt a thing. The slide dragging a bit on the top round is bound to move it some.

[WilliamG]

Oh for sure. But I noticed if I do a chamber check on the PM9 with a full mag, and then eject the mag, it's really quite a tug to get the mag out. More so than my other semi-autos.

[ATF]

I agree with Jocko too, (his heads swelling as we speak) give the spring a try. I wouldn't waste any time switching barrels. I'd wager up to a quarter that ain't the issue. I'm going with different ammo.

If he suspect the feed ramp is causing the issue then that's a feature that could indeed be different between both firearms. There probably isn't one smoking gun; most likely an interaction between two features that's causing his issue. In the interim while he's waiting on a part from Kahr he should definitely try swapping barrels; this idea can be ruled out in 10 shots at a local range.

[Bawanna]

If he suspect the feed ramp is causing the issue then that's a feature that could indeed be different between both firearms. There probably isn't one smoking gun; most likely an interaction between two features that's causing his issue. In the interim while he's waiting on a part from Kahr he should definitely try swapping barrels; this idea can be ruled out in 10 shots at a local range.

True. I would concede that it would certainly provide more information. His barrel might have a slightly tight chamber or something that would show up with the other barrel being ok. Something that could be fixed.
He would still need to stick with the same ammo that balked for a fair comparison.
I'm really curious what happens when he goes back to the Federal. If something has changed or strictly an ammo issue.

[ATF]

True. I would concede that it would certainly provide more information. His barrel might have a slightly tight chamber or something that would show up with the other barrel being ok. Something that could be fixed.
He would still need to stick with the same ammo that balked for a fair comparison.
I'm really curious what happens when he goes back to the Federal. If something has changed or strictly an ammo issue.

Agreed, definitely needs to fire ammo of the same type in both guns and preferably from the same box so that he can ensure that the ammo came from the same lot. This will help to eliminate any special cause variation.

[jocko]

how about

I am new here so I am sorry my first post is a plea for help. How did my Kahr CM9 experience go from great to awful?

First Range Trip

I took the CM9 to the range with only one goal. Put 200 rounds FMJ down range and break the pistol in. Using one six round magazine I put 200 rounds down range in two hours.

I must report one failure to feed at approximately round 180 loading the second round of a fresh magazine. Honestly after you have loaded 170+ rounds I could have just gotten careless and didn’t seat the round properly.
I honestly don’t know.

I cleared the jam and finished the 200 FMJ without issue.

I also ran a box of 9mm Winchester PDX1 +P without issue.

Never shot a PM9 so I can’t make the comparison. I can only say that I like this gun.

That’s my experience. No BS to make it sounds better than it really is.

Every visit since then..

All outings since I can’t run the six round magazine without a nose dive jam (round is wedged just below the feed ramp at a downward angle).

The nose dive jam always occurs on the second or third round.

Before I go on let me tell you the first round is chambered per Kahr specification. I also followed the prep instructions on this site.

I called Kahr to discuss the problem. I described it the same way as above. The Kahr representative asked if I was the first owner and my name and address (no serial number). He said they would send me a new recoil spring.
I had the opportunity to shoot the CM9 using a friends PM9 magazine. You see I initially thought the problem might be the magazine, but the CM9 jammed the same way with the PM9 magazine.

Is a recoil spring really going to address the problem?

looking at this suggestion. It coold be just a SWAG (scientific wild ass guess). but empty the magazine, take the floor plate off and pull out the spring and follower. Reinsert the magazine. Now slowly with the spring in place on the bottom of the follower slide it upward in the magazine. See/feel if there is a glitch/stoppage in the follower when it gets to where the magazine release button comes into that slot in the magazine. If so take the follower out and lightly sand the right side where it comes into that slot opening of the magfazine and retest again until it goes all the way up smoothly. We had a fellow poster awhile back with the exact same issue and this suggestion was presented to him and sure enough it was catching at around 2/3 as that is where that follower at that time is in direct contact with the magazine release button in that magazine slot opeining. He sanded his down until it slide by easily. I must admitr, that it did not solve his problem though but it is something to at least check out. Being you tried it with another magazine off of a PM9 which is the same magazine and it did the same thing on round 2/3 kinda tells me to look in this area. Your gun cannot count, it doesn't know round 2 from round 6. You as a shooter cannot produce shooter error all the time on round 2/3 either, so I am inclined to say it is not shooter error. This may not be even an isuse but it is something that you can check out in house with no shooting required.. You need to try to eliminate all possables. Every gun has its own personality and what didn't fix this other fellas gun mightt indeed be more severe in yours. It is worth a try.

another thing to try . take 2 rounds out of your 6 round magazine now load the gun leaving 3 rounds still in the magazine. See if it function perfectly.(by shooting it) By leaving 3 rounds in the magazine with one in the piple you have now let that follower slide past that slot opening in the magazine. . For if the gun screws up on rounds 2/3, it still should screw up then to.

[BEARDOG]

I am with Bawanna, What changed?

Things I would check or try first...
Since the ammo has been changed, definitely try the Federal again.
Did you tear down and clean and lube it in between? Is it reassembled correctly?
Are the recoil and magazine springs in correctly?
Is it lubed good? A high quality grease really slicks them up.
I always "pack" my mags by smacking the back into my palm, The Kahr single stack mags are a little touchy and really benefit from that IMO.
Is the feed ramp polished well? Try polishing it with a dremel and polishing compound, can't hurt to try to improve it.
Try the new recoil spring when it comes.

Just some things to try.
Good luck!