Thoughts on the CM9 feed issues

[D78999]

I have a little time, before I head to the range. I intend to give my new CM9 a real workout today - to try and finish the "break-in" process. I have put 80 rounds through it to date and I expect to pass 200 today.

I have had the 6th round feeding issue (nose-diving) from the beginning. So, I have been trying some things to remedy the situation. Using the slide release, as recommended by Kahr, helps, but does not produce complete reliability.

The feed ramp in these little pistols is VERY steep, as it no doubt MUST be.....there is no room for a more relaxed angle. The feed ramp is the entire "secret" of Glock feed reliability - an undercut chamber (which allows for a longer feed ramp) with a feed ramp angle as flat as possible. No room for such a thing in the little CM9/ PM9. So, I polished the feed ramp on my CM9. That changed nothing.

Early on, I realized that the mag spring was very tight when loading to the maximum (6 rounds, in this case). The mag spring was obviously closing completely, making it much more difficult to get the 6th round in. So, I took 1 full coil off the mag springs. This helped, though two coils might be better (but, I will see how things go as the gun is fully broken in, first).

Of course, I de-burred the magazine catch slot in the magazines, as well as going over the edges of the mag lips lightly with a file. I also worked over the magazine followers with fine sandpaper, to eliminate any binding. No help there.

I found, in testing my CM9, that holding my little finger under the magazine and applying upward pressure when racking the slide or sling-shoting it (with 6th rounds in the mag) solves the feeding issue. So, that will now be SOP for me, from now on. The mags have about 1/8" of play in the mag well, with the slide OPEN....and the mag sitting too low seems to contribute to the problem.

As for the recoil spring, I noticed that the spec'd (and provided) spring for this little pistol is an 18 lb. one - quite strong for such as small pistol, even with 9mm. Of course, Kahr specifies a strong spring because most people with these pistols just buy off-the shelf defense loads for them....and such rounds tend to be loaded hot (as well as +P and +P+ ammo, which some insist on using). But, for general use (I NEVER load that hot, myself)....I wonder if a slightly lighter spring might work OK. These small pistols are more susceptible to the effects of "limp-wristing" (than heavier ones) - and a moderately loaded cartridge has a lot to overcome with an 18 lb. recoil spring. I found that a spare 15 lb. S&W spring, that I had on hand, would fit just fine, if shortened. So, I will test BOTH today.

To sum up: the real, overriding issue with feeding problems in the Kahr CM9/PM9 pistols is obviously the very steep feed ramp angle. If this could be changed to a lesser angle, the problem would probably disappear altogether. The feed ramp angle is a compromise, to be sure. No room in these little pistols for a long, soft slope - and there's the rub. I do NOT believe that the problem lies with engineering or production quality of these pistols, but rather, only the compromise that had to be made with the feed ramp. After all, this sort of thing is not unknown - 3" "officer" sized 1911s are infamous for feed issues, because the necessary operations have to be accomplished in such a short length. The same applies here. As of yet, I have not come up with a complete solution. But, I am not worried. The pistol IS a quality piece, of that I have no doubts. It just needs a wee bit of "tweaking", as well as some common sense applied to the operation of it.

I'll report back, especially if I find anything that might be useful to the group.

[jocko]

nuttin wrongwith the feed ramps IMO, u just got a finicky kahr and there is sumpin upsetting the timing of the gun. Not sure about the lighter recoil spring thing doin any good either but ur not gonna hurt anything byu trying. If u took a file tothe mag feed lips surely u smoothed it out with some fine grit paper after that to. Is this the only magazine u have for this gun??? Do others do the samething. If u have an extra outter mag spring, just cout off one coil and test. At one time kahr made a lady PM9 which was basicaly astock PM9 with a 16# spring in it, so ur not gonna hurt anything. Awell broken in and smoothed out kahr might get by with a 16# spring but a new kahr that is tight might not feed well. It is all about perfect timing and ur working on it but ur not there yet. taking more coils off the mag spring might indeed make it asier to oad the magazine but again it might also slow down that magazine follower on the last round from presenting a round and also from locking open to. again it is all about timing and a magazine spring is part of the timing sequence. But aht weing said the worst u can do is ruin a spring, the best u can do is maybe fix ur issue.

What might fix ur gun, I do hope the forum members realize that ones fix for his gun is not a fix for ur gun, but it is something to always keep in the back of ur mind if your gun is giving issues such as posted..

How many actual coils is in ur cm9 recoil spring??? They use dto be factory 15 then kahr finaly relized that many could not get a new spring in the gun and had issues, so they went to the new standard 13 coil 18# spring. Which by the way u can now order them from wolffs gunsprings under the PM9 listings.. They offer factory weight of18 and a heavier weight of 20#, soetimes that 20# spring helps with feed issues..

[muggsy]

I wouldn't do anything to that CM9 until you've gone through the break-in period, except to clean and lube it generously. If you're still having feeding problems try a different brand of ammo first. Don't use the under powered, dirty, bargain basement ammo. Run in on good quality ball ammo during the break-in. Check your spent cases for scratch marks. If you find them scratched smooth the feed lips of the magazine using some fine emery cloth. If you're still experiencing feeding problems after 200 rounds post again.

[scosgt]

Some Kahrs just seem to be lemons.
After 3 PSL's in the first 200 rounds, my CM40 has been perfect function wise. It would not feed Fiocchi TEWB or whatever it is ammo, but works with every hollowpoint I have tried - Win 180 Bonded JHP, Speer Gold Dot, Winchester Ranger 135 GR JHP, and all the ball ammo (aside from the aforementioned Fiocchi, which I could not even get to feed on the first round).
My MK-9 was a lemon that had a PSL problem that could not be cured. It happens.

[scosgt]

Must add, when the gun was new I needed to tape the slide lock out with a plastic hammer and dig it out with a screwdriver. Now that I have several hundred rounds though the gun I can remove it with my hands. They DO break in.

[D78999]

I never suggested that my CM9 is a "lemon"....or anything like that. Quite the contrary. I only spoke about the full magazine mis-feed issue. That issue, whether anyone agrees or not, IS due to the really steep feed ramp angle. Nevertheless, that in no way makes the pistol a "lemon".

By the way, I don't shoot "white box", or any other commercial ammo, cheap or otherwise. Only hand loads. I have been hand loading for about 15 years.

As I said before, as if anyone actually read what I said, since I started wrapping my little finger under the mag, while chambering the first round from a full magazine (what I call my "little finger trick"), I have had NO mis-feeds.

I shot about 170 rounds today, at 12 and 25 yards. NO problems, accuracy was amazing for such a small pistol, and the gun was a pleasure to shoot.

I tried both the 15 lb. recoil spring and the standard 18 lb.....and there was no real functional difference. However, the feel was a bit different. With the 15 lb spring, recoil seemed a bit sharper, though still not unpleasant. So, the 18 lb. spring will stay in the gun.

So as of this afternoon, I have about 240 rounds through the CM9. The full magazine mis-feed continues as before, with whatever ammo I've tried (multiple bullet types in my hand loads), UNLESS I use my "little finger trick".

Regardless, I LIKE the CM9 very much. It is a keeper, regardless of the one issue. As soon as I put a few more rounds through it, if no other problems come up, then I intend to make it my EDC.

[RevRay]

I'll bet even that mis-feed problem will sort itself out eventually. These Kahrs tend to just get better and better. In fact, the best way to find a good Kahr cheap is to buy anything you see on Gunbroker or Armlist that says that it has only like 50 to 100 rounds through it. It's somebody's new Kahr that they didn't break in ... in just another 200-300 rounds it will be just fine. When I first bought my "used" CM9 about 4 months ago, I killed my fingers trying to get the slide stop out. Now, I could get it out blindfolded it's so easy.

[CJB]

You say you have a 6th round feeding issue? But you're describing a 2nd round feeding issue. Some clarity please!~

You're mistaken about the Kahr ramp, and here's how you can see for yourself. Take the pistol apart. Mount the barrel to the frame using the slide stop pin. No slide on the frame of course..... Now take a magazine with one round in it, and seat the magazine. Push the barrel all the way backward and down. Thats how it sits at the beginning of the feeding cycle. See the releationship of the top round to the chamber?

Nuff said.

[scosgt]

I never suggested that my CM9 is a "lemon"....or anything like that. Quite the contrary. I only spoke about the full magazine mis-feed issue. That issue, whether anyone agrees or not, IS due to the really steep feed ramp angle. Nevertheless, that in no way makes the pistol a "lemon".

By the way, I don't shoot "white box", or any other commercial ammo, cheap or otherwise. Only hand loads. I have been hand loading for about 15 years.

As I said before, as if anyone actually read what I said, since I started wrapping my little finger under the mag, while chambering the first round from a full magazine (what I call my "little finger trick"), I have had NO mis-feeds.

I shot about 170 rounds today, at 12 and 25 yards. NO problems, accuracy was amazing for such a small pistol, and the gun was a pleasure to shoot.

I tried both the 15 lb. recoil spring and the standard 18 lb.....and there was no real functional difference. However, the feel was a bit different. With the 15 lb spring, recoil seemed a bit sharper, though still not unpleasant. So, the 18 lb. spring will stay in the gun.

So as of this afternoon, I have about 240 rounds through the CM9. The full magazine mis-feed continues as before, with whatever ammo I've tried (multiple bullet types in my hand loads), UNLESS I use my "little finger trick".

Regardless, I LIKE the CM9 very much. It is a keeper, regardless of the one issue. As soon as I put a few more rounds through it, if no other problems come up, then I intend to make it my EDC.

D78, it is NOT supposed to work like that.
The first thing I would do is get a couple of boxes of factory ammo and see what that does. You should NOT be carrying reloads anyway, both for legal liability reasons (they tried to hang Zimmerman for his "hair trigger" and "extra round in the chamber" on his Keltec) because if you ever use it they will say you made "super loads" to kill people, and for reliability, because a shootout would be a really bad time to have a case split or a squib or a not fully seated primer.
No comment on your reloading prowess, just speaking common sense.

That being said, if factory ball or JHP feeds properly, you have an issue with your rounds. There is very little space inside a Kahr, and a little off on the OAL or shape of the bullet makes all the difference in the world.

Again, it should and must feed off the top of the mag. If factory ammo won't feed, send it to Kahr to be fixed. Your issue is unacceptable on a defense gun. What if it jams or you get a dud, and you need to do a clearing drill? You won't be able to get the gun back into service. NO GOOD.

[CJB]

Early on, I realized that the mag spring was very tight when loading to the maximum (6 rounds, in this case). The mag spring was obviously closing completely, making it much more difficult to get the 6th round in. So, I took 1 full coil off the mag springs.

My God, your another Einstein!~ At the rate you're going, you'll graduate from just being a Kahr Engineer to owning the entire god damned company someday! If only they had somebody like you already, they'd have gotten it right, and saved countless folks from greif.

Let me give this for you to consider. Consider how little the breach face moves backward in its cycle, beyond that point which will allow a cartridge to rise up to the feeding point at the lips of the magazine. The slid overtravel, as well as the speed of the slide, combine to determine how much time the cartridge has to rise. If the cartridge rises too slowly, then there are problems... as its not in place when the slide strips it into the chamber.

My question to you, Albert, is as follows: Do you suppose that a cut, shortened magazine spring will push those cartridges faster, or will it push those cartridges more slowly?