Pm 40

[100percent]

I have had my PM 40 for several years. I really love it's accuracy. I am not averse to recoil and the 40 isn't that bad.

I seem to limp wrist it and the gun doesn't cycle every time. If I hold it like I mean it everything is cool but one in 30 times I get a failure to feed.

I don't carry it because of this issue I think I need a model with a bigger pistol grip.

Any thoughts. Its not the ammo.

[b4uqzme]

If you are sure that's the problem,, I wouldn't worry too much. Chances are you will hold on like he!! if you are ever in a defensive situation.

Otherwise there's always the P40. And you'd probably feel that a K40 shoots like butter. And if you want to keep the same size, try an MK40. All good options. Good guns.

[warbird1]

Love my CW40. You can get 3 fingers on the grip. I have had zero problems of any type with it. Highly recommend it.

[TucsonMTB]

Any thoughts. Its not the ammo.
When I first started shooting my PM40, after owning a 100% reliable CW40 for several months, the PM40 didn't seem quite as reliable feeding some ammo. Ammo with really light bullets, like 135 grain Ranger JHP worked every time, even if I gripped the gun lightly. 180 grain Rangers JHP would only feed reliably for the first couple of rounds. Really hot stuff, like Double Tap, was a real problem unless I hung on tight, like you.

No worries! I loaded two 180 grain Ranger JHP rounds on top of the lighter 135 rangers for carry purposes and got on with life. The gun never had any issues, even during "run and gun" style BUG matches.

That was more than a thousand rounds ago, maybe two thousand. I don't really keep track. More recently, after the wear from the additional rounds, you can't make that pistol fail with a full magazine of 180 grain anything, including Ranger JHP, unless you really work at trying to induce a failure by barely gripping the gun.

Yeah, I am a very happy camper.

Please allow me to suggest that you find some ammo with lighter bullets that you can afford to shoot a lot. After several hundred rounds or maybe a thousand, revisit your planned carry load. If your experience is anything like mine, I think you will be very happy.

Best of luck, sir!

http://www.kahrtalk.com/picture.php?albumid=103&pictureid=626

[jocko]

I have had my PM 40 for several years. I really love it's accuracy. I am not averse to recoil and the 40 isn't that bad.

I seem to limp wrist it and the gun doesn't cycle every time. If I hold it like I mean it everything is cool but one in 30 times I get a failure to feed.

I don't carry it because of this issue I think I need a model with a bigger pistol grip.

Any thoughts. Its not the ammo.

doubt the PM40 is a hand cannon, lot of issues come from that recoil. We have more comments about recoil in the 40 cal kahrs than any utter claiber. There is a reason for that IMO...:amflag:

a 100 rounds at a range session for a PM40 is a real trial for many. a 100 rounds in a PMJ9 is just a breeze as the first and last round feels the same.

Keep ur sessions shorter and see how that works. like 50 or less rounds. Put some snap caps in with some live rounds and let someone load them for you and it will show mayse some shooting errors that you ever see because ur in the anticiaption mode of the gun going BANG. Snap caps done this way will sure show shooting errors to..:amflag:

This might not hjelp but it willcertainly not hurt either. Ur PM40 has the same 18# recoil spring as the PM9 and that always baffled me as the 40 is just alot hotter round. Wollfs offers a 20.5# recoi8l spring for the PM9/PM40. buy just the outter spring that is all that is needed. That spring will fit either the new or older style kahr slides to so u can't go worng in ordering it.. It might help take the gun a tad to. If I owned that PM40-, I would magna port it and really enjoy shooting it more:amflag:

[100percent]

Thanks Shooters,
My gun is an older model. I bought it used. It is in really nice shape solid black.

So a heavier recoil spring would/might make it more reliable.

I usually shoot 180 grain in it. Hand loads.
When I first got it my rounds did great in a glock. I found that the chamber on the Kahr was a lot tighter. A lot of rounds wouldn't chamber. Kind of complicated things. I made some adjustments in the loading process and due a drop test on every round. Ones that don't pass get digested by the Glock.

I get the same issues on various factory rounds.

I am going to look into the earlier version of the recoil springs from wolff.
thanks.

[100percent]

I'm getting ready to change the recoil springs on my pm40. Has anyone else dissassembled and changed the inner recoil spring on a kahr?

[jocko]

IMO I would not mess with that inner spring. Just change the outter spring as u see fit, . I have over 32K out of my PMJ9 and I have never touched that inner spring. If it ain't broke don't fix it. works for me. Just sayin

[100percent]

Thanks Jock
btw, should the open end of the outer spring go against the keeper or against the slide?

[garyb]

Check out the vid in the post "Why some Kahr owners have issues" in this section. There is a vid that explains your problem. Problem can present its ugly head with any light weight sub compact gun. Additionally....For sure, over shooting can contribute to your problem with limp wrist. You seem to know what is causing the problem, so, simply cut back on the number or rounds at each range session. Train with it more and concentrate on the limp wrist more, until your problem goes away. As far as being a reliable SD gun, b4ugzme is right....


Changing the spring or porting it won't correct your limp wrist, but you can do those things if they make you feel good....nothing wrong with the suggestions. You already seem to know it is how you are holding your gun.

[100percent]

Yes thanks for the post. Usually the gun does this when I first shoot it. I never shoot it too much, just enough to enjoy it. I like the post about using lightweight bullets too. Maybe I will try and use lighter charge weights. I have had this gun for 4 years now. Bought it used and don't know the history on it although a search reveals that the gun was originally manufactured in late 06 or early 07

When I say limp wrist. I don't mean that I am consciously holding it loosely. I have a pretty decent grip but I am in my 60's and don't have the grip I had 30 years ago. The gun cycles, ejects but sometimes the slide doesn't always have enough to close. It ejects the brass about 10 feet away.

[SDGlock23]

I notice too with my CM40 that if I'm gripping it very tightly it usually runs like a champ, but if I slack off and use anything less than a strong grip, usually that's when any problems, as few as there are, show up. When I'm shooting Glocks or something larger I can get away with a firm grip, but when I shoot the CM40 I have to maintain a somewhat strong grip.

[100percent]

At least I am not the only one who notes this with the PM40 sized gun. Thanks.


I notice too with my CM40 that if I'm gripping it very tightly it usually runs like a champ, but if I slack off and use anything less than a strong grip, usually that's when any problems, as few as there are, show up. When I'm shooting Glocks or something larger I can get away with a firm grip, but when I shoot the CM40 I have to maintain a somewhat strong grip.

[100percent]

The wolf springs for my PM 40 were a half inch longer than stock. I put them both in. Tried the outer only and the inner spring collapsed by about a 1/3rd. So I put in both. Had to use a bit of a torch to soften the red locktite on center nut. I didn't have any to replace it so I superglued it back before I screwed it back on.

Bottom line is that the gun is great. No ftf fte so far.
Thanks

[b4uqzme]

Those new springs should help reduce "felt" recoil too. Thanks for the update.

Did you say "superglue"? :eek:

[100percent]

yes a drop of superglue on the threads. It should hold fine.

[100percent]

I fixed my failure to feed with some elbow grease.

http://kahrtalk.com/showthread.php?p=294136#post294136

[100percent]

Well another week and I have been shooting my PM40 every day. No failures to feed.

It is better than ever before, recoil is now moderate, accuracy is great as before.

[100percent]

An update.
Last night I was shooting handloads per usual and noticed that I had to nudge the slide closed a bit a couple of times. Weird.

I took it apart for a cleaning which it needed and inspection and a bit more polish of the extractor. I am getting so I can detail strip the slide pretty fast.

When I put it back together I noticed that the recoil spring guide was sticking out of the front of the slide about 3/16" and the gun was about that much out of battery. I nudged it closed and it felt just like it did on my backyard range.

The recoil spring rides very close to the plastic body, at times I have had this issue but it went away with a rack or two.

When I laid the weapon with the slide off next to it this is what I saw.

http://veloliner.com/Kapm40/pm40bur.JPG
The spring retainer is working around and catching on the the plastic of the frame. You can see how well polished the spring retainer is, (I did that). Apparently when assembled the retainer catches on the the lip extending the end of the retainer out past the slide.

I took a razor blade and carefully removed the lip and various strands. Further testing during the the next few days.

Is this what they call a kit gun.

[TucsonMTB]

This might be one place where polishing is NOT a good idea.

That disk shaped end of the recoil spring is not designed to move around on the area where it contacts the front of the barrel lug, quite the opposite. Once in place, it should not move side to side.

On my PM40 with the most rounds, the flat bearing surface on the front of the barrel lug has a noticeably rough texture of fine machining marks. The surface of the corresponding, disk shaped end of the recoil rod that bears against the barrel lug shows no wear marks from any type of regular movement, so I suspect there is none. And, even though I do grease that area lightly, I would not expect any motion.

When I install the spring it almost snaps into place, once it is straight, and resists movement from side to side when pushed with a finger.

If you have a spare recoil spring that you have not polished and is straight thus not likely to slide off to the side from misalignment, this might be a good time to install it.

[100percent]

Point taken. It was digging into the plastic a lot before I smoothed it out. It snaps in good. I may need a new guide rod. Perhaps mine is worn. The gun has an unknown history. Thanks.

[garyb]

An update.
Last night I was shooting handloads per usual and noticed that I had to nudge the slide closed a bit a couple of times. Weird.

I took it apart for a cleaning which it needed and inspection and a bit more polish of the extractor. I am getting so I can detail strip the slide pretty fast.

When I put it back together I noticed that the recoil spring guide was sticking out of the front of the slide about 3/16" and the gun was about that much out of battery. I nudged it closed and it felt just like it did on my backyard range.

The recoil spring rides very close to the plastic body, at times I have had this issue but it went away with a rack or two.

When I laid the weapon with the slide off next to it this is what I saw.

http://veloliner.com/Kapm40/pm40bur.JPG
The spring retainer is working around and catching on the the plastic of the frame. You can see how well polished the spring retainer is, (I did that). Apparently when assembled the retainer catches on the the lip extending the end of the retainer out past the slide.

I took a razor blade and carefully removed the lip and various strands. Further testing during the the next few days.

Is this what they call a kit gun.


I compared your photo to my PM40. If we are looking at the same lip, this is perfectly normal. That was not your problem. JMO.

[100percent]

After owning my Kahr for nearly 5 years and having intermittent failures to feed during this time. I quit shooting it for a few years. In the last month I realized that there are few guns with the caliber to weight/size ratio and this is about the only gun in this size that was available.

I have been almost continuously shooting my Kahr, 10 rounds a day, for weeks now. Been working on it about every other day looking at the action, analyzing the recoil in slow mo.

Lots of polishing to improve the slide speed. Barrel ramp polishing. I think I have posted every thing that I have done with my nice but problematic PM 40.

I put in new springs a few weeks ago and it worked for a couple of weeks before my Kahr started not fully reloading (FTF) again. In hindsight I am believing the new springs forced the action together "fixing" the problem for a couple of weeks, at least until the extra power springs soften and shrink.

I am pretty sure that I have found the main root of my slide not closing fully every time as the gun reloaded. I noticed that the left side of the top of the barrel was hitting the slide slowing it down. It is hard to show but you feel it as you hand rack the slide slowly.

I polished a radius on the left side of the barrel where it contacts the slide with my ceramic stone and wow, the gun cycles a lot smoother. I put some rouge on the parts and will leave it there for while before I clean the weapon again. The gun cycles again with full loads.

Here is the area that I have modified.
http://veloliner.com/Kapm40/http://veloliner.com/Kapm40/barrelslideinterference.JPG

\http://veloliner.com/Kapm40/barrelslideinterference.JPG
Tonight I shot 3 mags full without any issues.

[TucsonMTB]

http://veloliner.com/Kapm40/barrelslideinterference.JPG

Your conclusion seems reasonable to me. Just for fun, I measured the clearance on mine using narrow strips of paper as feeler gauges. It appears that my PM40 has a clearance of a little more that 0.011" between the left side of barrel hood and inner surface of the rectangular recess of the slide that it fits into.

Oh, and this is not rocket science. I simply measured the thickness of the three stacked pieces of paper, that easily fit into this gap, using my digital calipers. The calipers gave me a readings between 0.011" and 0.012", depending on how hard I pressed the jaws together.

On my PM40, that clearance extends the full depth of the cutout in the slide

Disclaimer: I am so NOT a gunsmith, so don't presume this is "good advice". However, this particular PM40 has never Failed to Return to Battery in the manner you are describing.

It might be worth noting that, in my PM40, the side of barrel hood does not contact the left wall of the slide at any point visible from above. The clearance in the area forward of the square notch notch where you found interference seems to be a little more than 0.005".

Hope this helps . . .

[100percent]

TMTB
The slide barrel/interface on my weapon has a bit of clearance too, thanks for quantifying yours.

The slide does tend to come forward on the barrel touching on the left side, maybe that is how the tolerances stacked up. It had worn the black finish off the slide right at the contact point.

I figured that a slight radius couldn't hurt seeing as there was a large bevel on the right side of the barrel shroud. The contact between the two corners was slight, before I worked on it I could see the barrel slightly pop over the rim. Might be only a couple of thousands of an inch.

Initial testing showed promise.

[garyb]

http://veloliner.com/Kapm40/barrelslideinterference.JPG

Your conclusion seems reasonable to me. Just for fun, I measured the clearance on mine using narrow strips of paper as feeler gauges. It appears that my PM40 has a clearance of a little more that 0.011" between the left side of barrel hood and inner surface of the rectangular recess of the slide that it fits into.

Oh, and this is not rocket science. I simply measured the thickness of the three stacked pieces of paper, that easily fit into this gap, using my digital calipers. The calipers gave me a readings between 0.011" and 0.012", depending on how hard I pressed the jaws together.

On my PM40, that clearance extends the full depth of the cutout in the slide

Disclaimer: I am so NOT a gunsmith, so don't presume this is "good advice". However, this particular PM40 has never Failed to Return to Battery in the manner you are describing.

It might be worth noting that, in my PM40, the side of barrel hood does not contact the left wall of the slide at any point visible from above. The clearance in the area forward of the square notch notch where you found interference seems to be a little more than 0.005".

Hope this helps . . .



Found the same clearance on my PM40 barrel hood, which has had zero problems. No contact with the left wall of the slide. Fits like a glove with no wear on the slide at that point.

[100percent]

GIt has been 3 weeks and haven't had any failures. I still find myself checking to see if the gun is back in battery, a bad habit for sure.

A part of the problem is the sensitivity wirh cartridge length. It runs 95% with one cartridge length. Increasing the length by.01" makes the gun a derringer, the gun will only cycle 20% of the time.

I took a chance and lengthened the cartridge by another .01" and it does great. 100% reliability. My other 40sw guns seem to do fine with any OAL's.

I am shooting the Lee 175 grain cast bullet, it has a very wide meplate.