Unexpected Mag Drop - PM40 = Fixed! Big Smile!

[TucsonMTB]

This weekend, I found out how embarrassing it is to ask for a cease fire to go forward of the shooting line to pickup your full magazine after firing the one round.

Repeatedly. :o

One of my PM40's was dropping the magazine on the first shot (the one "in the pipe") with every full magazine. Quite a puzzle that I never solved by shooting left handed or by gripping carefully to avoid hitting the magazine release button.

Eventually, I did move back a bit so that the mag stayed on the bench rather than skittering into the gravel . . . most of the time. ;)

"What changed?", you might ask.

Would you believe that the stouter recoil of Underwood ammo was the culprit? With milder stuff, like Winchester Ranger that I carry, there were no unexpected mag drops during this range visit. Mag drops only happened with the Underwood stuff. Admittedly, I didn't shoot much other ammo because I didn't have much with me.

I did have two magazines with me. Both popped out every time while shooting Underwood. Oddly, my other PM40 has always liked Underwood just fine. I don't believe it has ever dropped its magazine unexpectedly regardless of the ammo in use. So, I am guessing it should be possible to get this gun to run with Underwood as well.

Of course the real concern is that this pistol might someday drop a magazine with carry ammo at a time when it matters. That would be a real bummer. :eek:

Has anyone else had a similar experience? Were you able to fix it?

[muggsy]

I never experienced the problem, but if it were my gun I'd replace the mag release button and spring. If you thought it was embarrassing at the range, think how embarrassing it would be in a SHTF situation. Be enough to make you blush.

[Bawanna]

I'd strip a mag down, take the slide off and insert the mag. See if the mag release is making full contact. I would think you'd see the off side not completely flush.

Muggsy might have it nailed on a weak release spring or maybe its not latch up properly. Just not hooking up good enough to deal with the recoil.

[TucsonMTB]

I never experienced the problem, but if it were my gun I'd replace the mag release button and spring. If you thought it was embarrassing at the range, think how embarrassing it would be in a SHTF situation. Be enough to make you blush.
Can't argue with that!


I'd strip a mag down, take the slide off and insert the mag. See if the mag release is making full contact. I would think you'd see the off side not completely flush.

Muggsy might have it nailed on a weak release spring or maybe its not latch up properly. Just not hooking up good enough to deal with the recoil.
Well, you both got me thinking about the engagement surface of the mag catch.

Back in April, Kahr replaced the cracked frame on this pistol. They included a new magazine in the package when they sent it back. I used that new mag for the initial test firing. To my surprise, during the first range session (with no modifications to the follower) I experienced none of the usual second round nose dives. So I'm guessing they may have "fitted" the mag catch when they rebuilt the gun to avoid contacting the magazine follower.

Just looking down from the top of the action, with an empty magazine tube inserted, I can see that the catch engagement ledge on my other PM40 is easily a third again wider than the one in the troublesome gun. :eek:

Looks like there is a new mag catch in my future. Might as well replace the spring too.

Thanks for your help! :)

[TucsonMTB]

Joe Mayo at Kahr has "entered an order for a replacement" catch, but in his email he does not sound convinced that's the problem and he wouldn't go for the new spring.

Ya know . . . I'm sort of stuck with the PM40 for the moment. But, one of these days someone else is going to build a pocket sized "fotay" caliber hand gun with a decent trigger.

[Bawanna]

Joe Mayo at Kahr has "entered an order for a replacement" catch, but in his email he does not sound convinced that's the problem and he wouldn't go for the new spring.

Ya know . . . I'm sort of stuck with the PM40 for the moment. But, one of these days someone else is going to build a pocket sized "fotay" caliber hand gun with a decent trigger.

Did he have any ideas on what he thought the issue might be? I'd lean more towards catch engagement than spring but I can't think of anything else that would contribute to the unwanted mag drop.

[TucsonMTB]

Did he have any ideas on what he thought the issue might be? I'd lean more towards catch engagement than spring but I can't think of anything else that would contribute to the unwanted mag drop.
He seems to think it is an ammo issue. Well, yeah, it only happens with the hotter stuff, like most people carry.

Here is his email response to my email message in which I described the more narrow catch area in the gun that drops mags and suggested a replacement catch and spring.


I have just entered an order for a replacement magazine catch body for you. Seeing that your pistol was built in April of this year I do not think that the magazine catch body has worn to the point that it would cause this issue, but I'm happy to send out a replacement if that is what you want us to do.

The spring that holds the magazine catch body into the frame is just a flat pin and will not require replacement as it doesn't take any wear.

I hope this does remedy the magazine dropping issue, but keep in mind that if it doesn't then it may very well be just the ammo.

[jocko]

b.s. on the ammo part. U don't make a gun that drops magazines with certain types of ammo. My bet the catch will take careof ur issues Tucson.

I know u know ur stuff to but if it does it with the new catch, then try left handed and jif still the same, kahr needs to look at it.

If themagaziner release button is flush with the right side of the fraqme, then it is either worn or out of spec as that is as far in as it can go. If u can insert the magaszine and try like hell \to physically pull it out and it won't come then the bang thing isn't gonna effect it unless a shooters thumb is acidently hitting it with that explosion happens

I think they should have sent u a new spring just to ease ur mind, not like were talking $500 bucks herre either..

[TucsonMTB]

b.s. on the ammo part. U don't make a gun that drops magazines with certain types of ammo. My bet the catch will take careof ur issues Tucson.
Thanks, Jocko!

I'm guessing that Mr. Mayo is not an experienced shooting enthusiast.

It's good that you are here to call "B.S." http://home.mindspring.com/%7Ejustsomeguy/thumbsup.gif

[jocko]

well think about it. how fokking dumb of a statement can it be.

best have a disclaimer in the manual stating hot defense ammo might cause premature mag release. WTF. I sometimes scratch my head, maybe tomuch even, as some of these kahr tech statements are making me bald. Just sayin

[gb6491]

The shape/size of the mag well can affect how the latch interacts with the magazine. The mag well on my CW45 is large enough that I can twist the magazine. Here's a photo that shows the magazine twisted one direction and the opposite, hopefully (sorry about the photo quality) you can see how that affects the magazine latch's position in the magazine:
http://i49.tinypic.com/2a6w6z7.jpg
Just a thought on the ammo: were there any marks on the nose of the top bullet in the magazine when it dropped?
One more question: do the magazines contact or come close to the feed ramp of the barrel in this gun?
Regards,
Greg

[jocko]

GB by twisint either one either way was u able top pull any of the magazzines out?? Both photos IMO show more mag catch than problalby is necessary even. If the oneon the right showed that much, the magazine follower would never clear..

Just askin.

[TucsonMTB]

The shape/size of the mag well can affect how the latch interacts with the magazine. The mag well on my CW45 is large enough that I can twist the magazine. Here's a photo that shows the magazine twisted one direction and the opposite, hopefully (sorry about the photo quality) you can see how that affects the magazine latch's position in the magazine:
http://i49.tinypic.com/2a6w6z7.jpg
Regards,
Greg
Great pictures as usual, sir!

Yes. My PM40's are like that too. After Bawanna mentioned it, I spent a fair amount of time last night with a bare magazine tube inserted in each gun, wiggling them around trying to determine why one drops mags and the other does not.

Compared to your pictures, the gun that drops mags appears to have less than half as much catch area protruding into the magazine tube. :eek:

Obviously, I couldn't measure it and would hesitate to estimate the dimension, but at both the minimum and maximum positions, the engagement appears to be less than half the widths showing in your pictures.

I wonder if a conscientious and good hearted gunsmith spent a little extra effort to make sure the catch would not interfere with the upward movement of the follower when Kahr replaced the cracked frame in April. No good deed goes unpunished, I guess. ;)


Just a thought on the ammo: were there any marks on the nose of the top bullet in the magazine when it dropped?

I was not clever enough to carefully examine the bullets for marks. Underwood used a Sierra gold hollow point bullets for this batch of ammo. They appear to be brass plated and seem to be very hard. So, I would be surprised to see any marks, but I just didn't look, sorry.


One more question: do the magazines contact or come close to the feed ramp of the barrel in this gun?

I believe the feed ramps on both my barrels have lots of clearance between the ends of the ramp and the magazine follower skirts. I haven't had a broken mag follower in the many months since polishing a little material off the ends of the ramps. ;)

[TucsonMTB]

WTF. I sometimes scratch my head, maybe tomuch even, as some of these kahr tech statements are making me bald. Just sayin
Thanks to your relieving me of that duty, I still have all my hair. But, if I thought harder about what people report from their Kahr CS conversations, I might not. ;)

Hey, I say dumb things too . . . just ask my wife. http://home.mindspring.com/%7Ejustsomeguy/icon_lol.gif

[Bawanna]

I suspect a new catch and you'll be Golden. If yours show half as much as Greg's there's not a lot holding those puppies in place with the substantial recoil of the fotay.

It'll be good to look at the difference when you get it.

[TucsonMTB]

Yep! I will break out the camera when the new catch arrives. Probably won't be as nice as Greg's pictures, but we will do our best. :)

[gb6491]

GB by twisint either one either way was u able top pull any of the magazzines out?? Both photos IMO show more mag catch than problalby is necessary even. If the oneon the right showed that much, the magazine follower would never clear..

Just askin.
No, I was never able to pull a magazine out by hand, but I did have magazine drops when firing it. Kahr sent me a modified latch that fixed the problem, but I think modifying the followers helped as well (the CW45 was dropping the mag with two rounds still in the magazine). Also, the extractor could hit the top of the Kahr magazines during slide operation, but I don't use them anymore and I don't have this happen using modified Officer's magazines. FWIW, my CW9's slide/extractor does not contact the factory mags and I've never had an issue with it.

..
I believe the feed ramps on both my barrels have lots of clearance between the ends of the ramp and the magazine follower skirts. I haven't had a broken mag follower in the many months since polishing a little material off the ends of the ramps. ;)
My apologies for not being more definitive:o, I was asking in regards to the ramp and the top of the magazine tube.


I suspect a new catch and you'll be Golden. If yours show half as much as Greg's there's not a lot holding those puppies in place with the substantial recoil of the fotay.

It'll be good to look at the difference when you get it.
I wonder if the catch they are sending a catch will be modified similar to the one they sent me for the CW45: http://kahrtalk.com/showpost.php?p=15667&postcount=2

Regards,
Greg

[TucsonMTB]

My apologies for not being more definitive:o, I was asking in regards to the ramp and the top of the magazine tube.
No worries! I just inserted an empty magazine tube to check. I am using unmodified Kahr magazines. With the generous cutout in the top of the tube, no part of the ramp comes anywhere near the tube, not even at the bottom of the ramp end or at the sides of the ramp structure. The only magazine component that comes close to (and used to make contact with) the ramp is the plastic follower.


I wonder if the catch they are sending will be modified similar to the one they sent me for the CW45: http://kahrtalk.com/showpost.php?p=15667&postcount=2

Regards,
Greg
Good question, and now that you call it to my attention, we should be able to check during installation. That said, the shelf on the catch in my reliable gun looks about a third again wider than the one in the gun dropping mags (consistently first and last rounds for me, by the way).

I like your theory about the dynamics of side to side magazine movement. Never thought of it but, there certainly is plenty of room for that movement in both of my PM40's. Both magazine wells measure 0.5170" in width, measuring between the plastic rail-like structure molded in, to guide and position the magazine. My magazines measure 0.4870" width at the point on the tube where those plastic bars or rails leave wear marks parallel to the direction of insertion.

Let's see . . . that's 0.0300" clearance available for side to side movement. Needless to say, my mags drop freely. http://home.mindspring.com/%7Ejustsomeguy/icon_lol.gif

[TucsonMTB]

Oh, and . . . thank you for the link to the catch replacement technique, Greg!

I can always count on you to be the "go-to-guy" for good technical info! http://home.mindspring.com/%7Ejustsomeguy/thumbsup.gif

[JERRY]

If the ammo makes the magazine drop during firing there is something wrong with the magazine or its catch. If the shooters thumb inadvertantly depresses the mag catch enough to drop a mag from a firing grip there is something wrong with the magazine or its catch as well.

It should take a solid and deliberate push on the mag release to disengage it, all this shooting grip in the way or ammo blame are excuses for a less than thought through design.

Naa guardia .32acp had that issue so they sent out more stout mag catch springs to solve the problem. No excuses just solutions.

[TucsonMTB]

Actually, JERRY, to my knowledge, I have never caused an unwanted ejection by hitting the magazine release while shooting. At least on mine, it takes a conscious push to eject the mag.

In the case of this gun, firing the first and last rounds was consistently causing an ejection. Even if I wanted to, I probably couldn't do that with my hands while shooting. I'm not that dependable. Just ask my wife. :rolleyes:

[JERRY]

TucsonMTB, there you have it, a gun problem not a shooter's grip or ammo problem.

other than poorly finished feed ramps/throats, the magazine or its assessory parts are the achilles heal of a semi-auto, still......

[TucsonMTB]

Today, we shot 50 rounds of Remington UMC "Target" ammo, (40 S&W, 165 GR. MC LN40SW4).

The magazine popped out just before feeding (not feeding, actually) the last round every time.

With one round in the mag when it popped loose, it only dropped a quarter inch and stayed in the gun . . . but, it was still a P. I. T. A. http://home.mindspring.com/%7Ejustsomeguy/icon_lol.gif

Tomorrow, I will just shoot a 1911. http://home.mindspring.com/%7Ejustsomeguy/thumbsup.gif

[Bawanna]

Today, we shot 50 rounds of Remington UMC "Target" ammo, (40 S&W, 165 GR. MC LN40SW4).

The magazine popped out just before feeding (not feeding, actually) the last round every time.

With one round in the mag when it popped loose, it only dropped a quarter inch and stayed in the gun . . . but, it was still a P. I. T. A. http://home.mindspring.com/%7Ejustsomeguy/icon_lol.gif

Tomorrow, I will just shoot a 1911. http://home.mindspring.com/%7Ejustsomeguy/thumbsup.gif

Was this with the new mag catch or the same original, has to be the original, haven't had time to get a new one yet. There's still hope?

[TucsonMTB]

Was this with the new mag catch or the same original, has to be the original, haven't had time to get a new one yet. There's still hope?
Still hoping for a replacement mag catch. But . . . Friday, when Eoin Pryal responded to my original email, he said he talked with one of Kahr's gunsmiths whose opinion was that it is not a problem because there is other ammo available that works. Unfortunately, the only other ammo I have that works is my 135 grain carry round.

I guess I will have to call on Monday to see if they have sent or are planning to send a replacement. Otherwise, I will just order a couple myself.

The only rub is that Greg indicated they supplied a modified catch to him when he had a similar issue. It is not clear if this is what they would ship if I order one or two. :rolleyes:

Admittedly, I could just do a little grinding myself . . .

[Ljutic]

I have this same problem with the PM45 I am borrowing. The owner insists it's caused by the offhand thumb activating the release when the PM45 does the roll to the left thing during recoil. I'm not so sure about that, but I do know it's a huge PITA to deal with. I had to shoot the Recoil Cam 3 times before I finally got a clean run without the mag dropping out of the pistol.

If it was my gun, I would be calling Kahr to discuss the issue. The owner seems to think he can shoot around the issue.

[TucsonMTB]

I have this same problem with the PM45 I am borrowing. . . . The owner seems to think he can shoot around the issue.
Yeah, it's almost like children. Sometimes we have a hard time admitting how ugly our own baby is. :o

When the mag drops first started happening, I thought it was limited to the one brand of ammo that I was practicing with. This weekend it started happening consistently with another brand of practice ammo.

Now, all I have to do is convince Kahr that "we" really do have a problem.

Kahr was very quick to tell me the gun was "OK" when I had only experienced mag drops with one brand of ammo. :rolleyes:

Reminds me of that line from the movie Cool Hand Luke (http://en.wikipedia.org/wiki/What_we%27ve_got_here_is_%28a%29_failure_to_commun icate), "What we have here is a failure to communicate." I blame myself for being too nice a guy in my first email to Kahr CS. Kahr is not Wilson Combat on your side.... (http://www.wilsoncombat.com/kniveswt/wilsontactical/menu.htm) .

Here's hoping they can just send a better functioning mag catch and spring combination that I can install myself. I really do NOT want to send this PM40 in again.

[espresso]

I received my new mag catch and mag catch spring from Kahr Fri for my CW9 which is also dropping mags. The mag catch seems harder to press so I hope all will go well at the range.

Tuscon, I didn't have any problem getting them to send it out no charge as my gun is under warranty I spoke with Ian. I can tell you one thing I will not shoot around this. If it's not fixed I'm sending the gun back to Kahr.

I haven't had a chance to go to the range and it may be a while before I get around to it as we are preparing for a hurricane :32:

I'll report back when I get a change to shoot her.

[TucsonMTB]

Good luck with that hurricane, Mr. espresso! Once you are safe, I will be very interested to hear how your range session goes.

I called again this morning, the call was taken by "Kate". When I told her the magazines are dropping out of my PM40, she asked for my mailing address so that she can "order a warranty replacement mag catch".

When I asked, she described the replacement as not being different from the original other than being less worn. By her estimate, it should ship in "a few days" and should arrive in "about a week and half" by US Mail.

I have my fingers crossed that replacement catches will help both our guns.

Edited to add: Lessons learned . . . Call, rather than email. Provide as little detail as possible so no one over-thinks the solution. Hey, my wife always says I am "trainable". http://home.mindspring.com/%7Ejustsomeguy/icon_lol.gif

[LorenzoB]

yeah, it's almost like children. Sometimes we have a hard time admitting how ugly our own baby is. :o
...

LOL!!! That is too funny!

[TucsonMTB]

The mag catch that Kahr shipped last week has arrived. Today, I wasted no time installing it and went directly to the Pima Pistol Club range to test.

No failures of any kind with any of the ammo I have on hand! :D

This gun has fired something around four or five thousand rounds. About 400 rounds ago, it was rebuilt by by Kahr. They replaced the frame that had cracked. From the difference in dimensions between the original, problematic catch and new one (pictured below) I'm guessing that they re-used the magazine catch when they assembled the gun on the new frame.

http://viewsfromtucson.com/wp-content/uploads/2012/08/Catch-Measure-2.jpg

Either that, or the original mag catch was fitted at some time (not by me) to prevent hanging up the magazine followers on the second round. I say that because the unmodified, new magazine Kahr shipped with the gun did not experience any second round nose dives when put in service immediately after the gun came home.

Whatever . . . with the new magazine catch in place, the gun now runs perfectly again.

Life is good! http://home.mindspring.com/%7Ejustsomeguy/thumbsup.gif

[Bawanna]

I'm bawling my eyes out, I'm so happy! Timing was perfect, just when I was gonna throw in the towel over getsomes woes, we get a tid bit of good news. Life is still good.

It'll be even better if I can open a can of whoop arse on a property room thief.

[espresso]

Great glad to hear that Tuscon!

I'll test out my new mag catch sometime after this dang storm does it's business.:mad:

BTW I'm just out side Baton Rouge about an hour away from New Orleans and we're starting to get some big wind gust now. Only a Cat 1 but the middle of the storm is due to go right over our heads.

Don't know how much longer I'll have power but were as ready as we can be......

[TucsonMTB]

. . . I'm so happy! Timing was perfect . . .
Thanks for the good thoughts. We aim to please!


It'll be even better if I can open a can of whoop arse on a property room thief.
Go get 'em, Tiger! :eek:

[jocko]

nice job tucson, I wouldlike tothink mayb ekahr has addressed the mag catch thing alittle more seriously, as ustatedone willnot know if ur original catch was moded by the owner or just abad catch or what ...

I know back ion the eralier days were were recommending do the mag releasemod before we discovered the follower fix which seemed quicker and lett work involved..

[SC_Dave]

FWIW, I gutted my mag for my CM9 in order to see how much of the catch was protruding into the mag. I can't measure it for sure but it's minimal, maybe 1/32 of an inch. So far, I have not experienced unexpected mag drop even with +P Gold Dot. I'll shoot more +P next weekend and post if I have any trouble. After more wear who knows, it doesn't look like it would take much at all.......
David

[jocko]

well if it protrued to much then it would be grabbing the magazine follower and other issues would rear its head. Another reason why there really shouldn't be alot of side slop on the mag well, to much and u might get premature mag dropping. If all is well, then proceed to the. "IF IT AIN'T BROKE DON'T FIX IT."
Most premature mag issues are out of spec mag release button, a replacement usualy takes care of that. Kahr is pretty good about sending out that to, for they don't wantto have to send it back and and forth on their dime when they can try this fix first. Next premarture mag drop is usually shooter error/thumb issue. I being a lefty seem to never have this issue with mag release or slide lock lever

[espresso]

FINALLY got a chance to test out my CW9 after kahr sent me new mag catch and mag catch spring because my mag was dropping while shooting.
50 rds 147 gr
50 rds 124 gr
No mag drops--she worked like a Timex!
Life is good...........