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Thread: CW45 (and other poly 45): issues and fixes

  1. #1
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    Default CW45 (and other poly 45): issues and fixes

    I’ve posted fixes to some issues that I’ve had with my CW45 on this and other forums.
    I thought I would consolidate them here.
    A note: I’m sure that Kahr would have taken care of all these, but I’m a “hands on” type and prefer to do the work when possible. My methods and solutions might not be best for everyone and as such the following information is intended to show how I did it. It is not intended as a “how to” article. Proceed at your own risk!

    BTW: If anyone else has some tips, fixes, upgrades to the poly 45s, please feel free to post them here

    Very useful links:

    Disassembly/Reassembly Of the Kahr P45 Pistol
    How To "Detail Strip" the Kahr's Upper!
    Kahr Polymer Frame Disassembly (Tutorial)


    Night sights:
    I installed the night sights on my CW45 and I'm very pleased with them.
    Some thoughts:
    - The sights are well made. I would prefer Meprolight sights and their sealed capsules, but oh well.
    - The stock front sight snaps off (per instructions) very easily.
    Here (verbatim) are the instructions for removing the front sight:
    "Removal of the Existing Front Sight
    1. Using a small set of vise grips, being careful not to make contact with the slide, grip the front sight and pull to remove the upper half.
    2. Using a pick or very small Phillips head screw driver push the remaining portion of the polymer posts out of the slide from the top of the slide. Be careful not scratch the top of the slide.
    3. Turn the slide over and ensure there is no remaining polymer in the front sight holes of the slide. If there is, gently remove it using the pick or small Phillips head screwdriver."

    I used masking tape to cover the slide around the front sight blade. I put the vise grips on the front sight blade with the jaws standing off from the top of the slide and pulled the sight off with a slight rocking motion. The posts and sight body separated quite easily. The posts and residue (the posts are melted to stake the sight on) were also removed with little effort.
    - The new front sight has two posts; one is threaded. The sight is attached with a Phillips head screw and red Loctite.
    (see more detailed installation info in post #27 http://kahrtalk.com/showpost.php?p=54961&postcount=27)

    - The stock rear sight was very hard to remove. I actually damaged my sight pusher and finished the removal with a large brass punch and hammer (sight appears undamaged).
    - The rear night sight needed a slight amount of material removed for easier installation; after that, installation was easy with the undamaged side of my sight pusher.
    - I really like the sight picture.

    - I think the front night sight should be offered by itself as it is definitely an upgrade over the stock item (it really did snap off easily). In retrospect, I would have been happy with that and have an undamaged sight pusher. I also think that a "front sight only upgrade" would be a very "doable" DIY project for most owners.
    UPDATE:
    I was able to purchase the Trijicon front sight by itself after contacting a Kahr sale representative: also, Dawson Precision now offers front sights for Kahr CW series pistols: www.dawsonprecision.com SIGHTS FRONT:Kahr Front Sights Category
    See the Dawson night sight installed here: http://kahrtalk.com/showthread.php?p=59903#post59903


    BTW: I've been very pleased these sights. Here's three magazines worth of 230gr. hardball, fired at 10 (2 ea.) and 25 yards, two handed standing:



    to be continued...

  2. #2
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    Magazine prematurely dropping out of the pistol (next to last round):
    (if your gun is doing it on random round counts, you might want to see reply number 42 for jhertzler's fix )

    I’m not the only one who has had this issue; here is my reply on another forum:
    The magazine self-eject usually happens on the next-to-last round.
    My pistol did this and a new latch fixed it.
    A few words about the new latch: I called Kahr and explained my problem;the tech I spoke to immediately said he would send me a new latch. The latch arrived quickly (kudos to Kahr), A quick inspection showed that the new latch is similar to the old one, but the shelf on it had been machined at a slight angle and increased area:

    *Note about latch spring installation at bottom of this post.


    Now, that is all well and good, but I’m began to wonder why the original latch always dropped the magazine with two rounds in the magazine and not some random sequence.

    Here’s my conclusion:
    There is some side to side play of the magazine when it’s in the magazine well. With the top end removed and a magazine (sans follower and spring) in the well, if you twist the magazine base back and forth, you will see that the magazine latch stays engaged in the magazine, but that depth of engagement varies from just enough to quite a bit inside the magazine body. The latch itself does not move during this evolution. Now, my first thought was that the bullet noses were somehow disengaging the latch if the magazine twisted when there was minimal amount of latch engaged. Inserting a loaded magazine into the well, I twisted it back and forth trying to disengage the latch; no luck perhaps recoil forces are more violent and could do it. Then I tried stripping rounds out of the magazine to see if that bumped the latch out of place, no joy or movement until…the follower came up in the magazine latch cutout window.
    Here, I noticed that the magazine latch moved; twisting the magazine at this point caused the magazine latch to move quite a bit, but not enough to disengage the latch. However, the most movement of the latch occurs at this point and this point happens to be at the magical two rounds left in the magazine mark.

    So what gives? I believe that when the follower is at this position, during recoil the magazine twists, pushing the latch out of the frame and then twists the other way faster than the latch can sometimes react. The magazine’s spring tension and forces from the slide working over it (possibly causing it to twist as well) push it down and out of engagement while the latch is playing catch up. Note: Add to the proceeding that it might be possible that the slide is hitting the magazine, which could possibly push it out of the latch's grasp. (http://www.youtube.com/watch?v=3EBWZvFBeUY). I believe this is why the modified latch works: the magazine would have to move slightly upward to disengage from the latch making it a little more difficult to shake loose from or possibly limiting how far the latch is pushed out from the frame. A stronger magazine latch spring would probably work as well and I believe that pistols that do drop magazines probably have a less than optimal spring (for the OP: replacing your current spring might be a good idea) vice a bad latch (though the machined latch makes up for this as a repair). Still, I worried that the problem could return (big trust factor issue) and turned my attention to the magazine follower. I believe that the magazine follower would benefit if it was redesigned in a manner that would significantly reduce the chance of a marginal latch, latch spring, or both allowing a magazine to drop. The follower simply needs to be made so that it does not contact the latch at anytime. To prove this to myself, I marked the area of the follower that appeared in the latch window, then reshaped the upper portion of the follower and cut off a portion of the skirt. Now, the follower does not contact the latch at any point. I can twist the magazine to Hades and back while the latch stays in place (no movement at all). The original magazine release now works as intended (no more drops) and the magazine (in regards to this) also functions flawlessly.
    Magazine latch window (OEM follower on the left, modified on the right):


    Left, OEM follower (notice areas contacted by the magazine latch) 2nd from left, Modified follower.
    UPDATE!!! - I now prefer to grind/sand/file the follower skirt for clearance vice cutting it (see right two photos). The upper part of the follower still needs to be reshaped for clearance as shown in the photo of the modified follower.

    *If you are doing this mod to eliminate nose dives, you may not need to remove as much material as shown here. Try removing just enough material to allow the follower to pass the magazine latch without issue. You can usually see where the latch is being scrapped by the follower. (see this photo: http://i51.tinypic.com/2zf0qxk.jpg )

    Disclaimer: I imagine there are quite a few (most?) CW45s out there that do not have this issue. I further believe that the modified latch and a new/stronger latch spring would fix/prevent the issue. Regardless of this (and for my own peace of mind) I'm going to run the modified magazines in my gun.

    *Latch spring installation:
    The spring is a press fit into the polymer, the magazine latch/catch (when installed) prevents it from working out of place.
    To remove the latch, use some type of tool (I made one from a coat hanger) to push the latch spring over and out of its slot in the latch. (Alternately: push the latch in and hold the spring over while pulling the latch back; lift/pry/ the end of the spring out when the latch clears it).
    With the spring end out, the latch can be pushed out of the frame.
    To remove the spring: just pull it straight up until it comes free.
    Compare the new spring with the old, some new ones have been reported oversize and may need fitting.
    Looking down into the mag well, you will see a wedge shaped cavity in the front strap (just below the magazine catch). There is a hole into the polymer at the bottom (small end) of the wedge. Hold the spring with needle nose pliers or a hemostat, then insert the spring into that hole; use enough pressure to get it started. Release the spring, it should lay pretty flat and parallel to the front strap; put a pin punch on the visible end of the spring and push it completely into place. Look through the magazine catch round hole, the spring end should be about quarter height up in the hole (see photo below).
    To install the catch, start the catch slightly, pry and hold the spring away from the front strap, push the latch into position, release the spring and slide the end of it into the cutout in the magazine catch/latch body.
    Done.




    to be continued...

  3. #3
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    Last round jams:
    The problem is very well documented in this post ( http://kahrtalk.com/showthread.php?t=1290 ) by gj47 in regards to his PM45:


    "The malfunctions occurred on the last round fired and cannot be cleared quickly. Notice that the casing was pulled into the mag feedlips and wedged into mag and ejection port area. The mag cannot be removed until the casing is pried out. The feed lips of this mag are now bulged about 6 thousandths."

    My fix as posted on another forum:
    “I've had two major issues with my CW45 and modifications to the magazine have fixed both.
    FWIW, the other problem began at about the 500 round mark; the last round would fail to eject cleanly: sometimes getting jammed back down into the magazine. What I found was that the magazine lip on the ejector side was tipping the last round in the magazine slightly upward and slightly off the extractor before it got to the ejector in the ejection cycle. When this happens the case often does not clear the ejection port and gets driven back down into the magazine or barley ejects (more like falls). With rounds still in the magazine, spent casing are (usually) held high enough by the following rounds that this would rarely happen.
    To counter this (a new extractor and spring might fix it), I decided to take some material off the magazine lip. I was pretty aggressive on the first magazine; I cycled a spent casing by hand and removed material until I felt the casing would stay in place long enough to hit the ejector. I took less off the next magazine and it seems to function fine. I imagine, with some patience and testing at different stages in the process that even less material would need to be removed. No more FTE issue with the modified magazines: also, they hold the rounds securely and I've had no feed issues with them (I've even dropped them a couple of times with no lost rounds).
    Stock magazine and modified magazine (right):

    Modified magazines: the second one done is in the background; the modification on it closely follows the contour of the stock feed lip on the other side of the magazine:

    I'm not saying this will work for all; it's just something to consider if someone's gun is malfunctioning as described above (again, this just how I did it; not a "how to" article).”

    to be continued...

  4. #4
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    Difficulty inserting magazine or stripping first round:
    Wyntrout describes (with photos) the problem very well in this post about his PM45:
    “I found the reason for the "crunch". After after comparing PM45 parts to their PM9 counterparts and screwing with a lot of the parts of the PM45 that I shouldn't have, I tried sticking loaded magazines in each and trying to see a difference. I found a big one. Look at the first 2 photos #43 and #48. These are of the PM9 with a loaded magazine inserted. Notice that there is about 3/16" between the rear of the cartridge and the striker housing and the lower ridge of the slide that strips the rounds off the magazine as the slide returns to battery position.
    Now look at the next 2 photos of the PM45 with a loaded magazine inserted and locked in place. There is NO clearance and the ramp/stripper/striker housing is resting on top of the base rim of the cartridge. This is why when the slide is released the stripper rides over the cartridge pushing it back down into the magazine and you have an empty chamber and a scratch on top of the cartridge. The magazine IS locked into place, but by squeezing the top of the slide and the bottom of the magazine hard enough the stripper mashes the rim which gives enough that cartridge is pushed forward of the stripper. That was the "crunching" sound.
    Clearly something is wrong here. Both pistols have the slide locked to the rear and there is a big difference in the gap on the PM9, or lack of one in the PM45.
    You guys with PM45s please look and see if there is a gap in your pistol between the rear of the cartridge and the stripper/striker housing. This is a big flaw and I think the magazine well is too far aft at the top or some other things are wrong. This sucks!
    Wynn


    I added a 5th photo of the top round in a magazine which gets scraped as the "stripper" rides over it. This happened a lot."

    Attached Thumbnails (see thumbnails here: http://kahrtalk.com/showpost.php?p=13828&postcount=11 )

    Note: Basically, the top round is getting trapped under the slide (Wyntrout photo):


    My fix: http://kahrtalk.com/13845-post21.html
    Quote Originally Posted by wyntrout View Post
    ...
    As an emergency measure, I could very slightly round the bottom of the "stripper" but that might screw something else up. This isn't an emergency, though....
    Actually, that's sort of what I did to fix the same problem (actually, I could not get my magazine to seat) with my CW45. I slightly changed the angle that the slide is beveled to where the rim of the round contacts it.
    In the photo below, I stoned the bevel so that the tailing edge of it is moved further rearward (red arrow). I did not change the starting point of the bevel (green line).

    The magazine now cams/rocks forward into place: the top round ready to be stripped out of the magazine. In the photo below, the shot on the left was taken just as the round contacts the slide; on the right, shows the magazine seated:

    A quick movie of the action:
    YouTube - slidemod.MPG


    Quote Originally Posted by a.squibload View Post
    Sorry about that, can't help myself.

    In your video, after the magazine seats it looks like the case rim is tight against
    the breech face (proper term?). Will the slide move any farther back from lock?
    SWAG that the slide lock might be at fault? Bevel looks like a good fix.

    Wondering if your slide's rearward travel is restricted somehow, don't know enough about it,
    is there a buffer? Couldn't be dirt on a brand new piece, maybe a burr? You've had it
    apart, probably would have seen that.

    PM40 suggested technique is to lock slide, insert mag, release slide.
    When new, mine wouldn't feed cycling by hand, only by releasing the slide lock.
    Tried it again recently, now it works by hand.
    Once the magazine seats there is a little space between the round and the breech face:

    The slide can be moved a little further back: enough to release the slide lock.
    I have another slide lock (a MIM piece), but there looks to be no difference in position when it is installed.
    No buffer, there's nothing I've seen that looks like it's limiting the slide's travel. I did this tweak some time ago and have had not had the problem since (I'm up to about 750 rounds through it).”

    to be continued...

  5. #5
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    Reduced profile slide stop:
    Some info here:http://kahrtalk.com/showthread.php?t=1099
    http://kahrtalk.com/showthread.php?t=3304
    Quote Originally Posted by gb6491 View Post
    Same here, I used a Dremel to knock down the sharp edges and corners on my slide stop.

    Regards,
    Greg
    Even more reduction (somewhat following Jocko's lead here http://kahrtalk.com/showthread.php?t=859):

    Compared to an unmodified stop:


    Slide locking back prematurely (aka locking back with rounds still in the magazine):
    I first thought this is to be an operator issue, so I removed some material from the stop lever to make it smaller and reduce the chances that I was inadvertently hitting it when the gun recoiled (see above). I'm not sure how much this helped as the problem still persisted.
    The slide stop on my CW45 was always very easy to remove from the pistol; so much so, that if a round nose dived enough while feeding it could pop the stop out from the frame. My first fix for this was to remove some material from the stop where a nose diving round would impact it. This did fix this issue, but I still had intermittent problems with the slide locking back with rounds still in the magazine. I decided to also remove some material from the stop where rounds might contact it when feeding from the magazine. This has fixed premature slide lock problems in other Kahr poly guns, http://kahrtalk.com/showthread.php?t=6066 (you might also want to see this video: http://www.youtube.com/watch?v=ph41eu-7IgI ), but was not quite as effective in my gun.
    I now believe that the slide stop spring may have played a greater role in both issues than the stop itself
    . I had an extra slide stop spring and decided to install it to see if it made any difference in how easy my stop was to remove.

    A note here: if replacing the spring, don't remove the screw holding the spring and washer in place completely out of the frame; just loosen it enough to remove the spring. This will greatly reduce the chances of stripping the threads in the polymer frame. (see how I did it here: http://kahrtalk.com/showpost.php?p=44744&postcount=25)

    Upon removing the spring, I compared the old and new: finding that that old had some wear marks on it where the stop contacted it, but otherwise they were identical. After installing the new spring
    , I did some experimenting with the screw that holds it in place (Note: I was very careful when doing this so as to not over torque the screw and damage the frame). I found that by tightening it just to the point that the spring seems to operate as two distinct springs (where before, the whole spring seemed to move easily as one) made for a much tighter fit of the slide stop. I say seems becuase you may not be able to eliminate all movement along the length of the spring, but just limit it how easily it's done. YOU DO NOT WANT TO OVER TIGHTEN THIS SCREW. I then loosened the screw until the spring would move freely as it had done before; this resulted in the stop being as easily removed as it previously had been. I played with how tight the screw was until I found a median that I liked; leaving it just tight enough that the springs travel seems to mimic two distinct springs and the stop is tight enough that I need to use something to start it out of the frame (though I can do it by hand if need be). My CW45 functions perfectly with the spring adjusted this way: no more inadvertent "lock backs" or the stop being pushed out of the frame by nose dives. Again, this is just what worked for me and how it did it, not how to do it.

    Here's a video to better explain (hopefully) how I tightened the slide stop spring screw: http://www.youtube.com/watch?v=c50P7HCAATo

    Later on: I found this posted about tightening the slide stop spring:

    I also called tech support to get the proper way of setting the screw and they said:
    The spring looks somewhat like a G and that the screw should be tight enough that the top and left part of it do NOT move. If I understood him correctly, the bottom perhaps from
    6 o'clock
    and going counter clockwise should move and that the rest should be clamped down. (http://kahrtalk.com/showpost.php?p=3...stcount=post20)

    This seems to verify what I found when replacing my slide stop spring.
    FWIW: I've been running my larger slide stop (unmodified lever) since replacing the spring (and tightening it as described above) and have not experienced any more premature locking back of the slide (or the slide stop being pushed out by nose dives).

    Slide stop popping out:
    Slide stop pops out when firing or chambering a round.
    Tightening the slide stop spring screw (as detailed above) may solve this issue for you.


    to be continued...

  6. #6
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    Reinstalling the slide:
    My CW45 has always required a slight manipulation of the trigger during reassembly.
    The rear of the slide first encounters a slight resistance, then passes over the cocking cam; at this point, the slide's position is quite similar to that in the OP's photo and cannot be moved any further rearward. Pressing the trigger lightly at this point allows the slide to continue backward a slight amount and the slide stop can be installed. I believe the slide is catching on the trigger bar and the slight movement of the trigger frees it up for the remainder of the required distance. The gun operates fine when fully assembled.
    Video of the sequence required on my pistol:
    YouTube - cw45.WMV
    Regards,
    Greg

    Flush fit magazine:
    See this thread: CW45/P45: Flush fit magazine - UPDATED


  7. #7
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    Quote Originally Posted by gb6491 View Post
    Reinstalling the slide:
    My CW45 has always required a slight manipulation of the trigger during reassembly.
    The rear of the slide first encounters a slight resistance, then passes over the cocking cam; at this point, the slide's position is quite similar to that in the OP's photo and cannot be moved any further rearward. Pressing the trigger lightly at this point allows the slide to continue backward a slight amount and the slide stop can be installed. I believe the slide is catching on the trigger bar and the slight movement of the trigger frees it up for the remainder of the required distance. The gun operates fine when fully assembled.
    Video of the sequence required on my pistol:
    YouTube - cw45.WMV
    Regards,
    Greg

    In addition to the stickies posted at the top of this forum, I found this a good read:
    Disassembly/Reassembly Of the Kahr P45 Pistol
    Thanks for sharing, glad things are working out!

    A Conceal Carry Handgun Must Meet a Minimum of Four Conditions:
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    4) It should fire a cartridge of sufficient power.

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    Good stuff, you really put some effort into this. Thanks.
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    gb6491, I would add that Kahr's "fix" of beveling the "stripper" doesn't move the cartridge, it pushes on the rear of the cartridge and moves the top of the magazine forward while the cartridge remains all the way to the rear of the magazine. I checked and double-checked that. Evidently there is a bit of extra space (or slop) in the top of the magazine well. The bevel and a new ejector seemed to fix everything, including the spent cases being ejected at my forehead. I will wear my Kahr cap every time I go to the range now, as well as shooting glasses.
    The missing "notch" for the recoil spring movement in the front of the slide is a biggie, too. Some guys have chosen to "machine" that as it should be instead of sending it back to Kahr... especially if you have to pay the shipping.
    Nice post. Thanks.
    Wynn
    The thin metal unmachined notch area:

    http://kahrtalk.com/showthread.php?t=1144

    The notch as it should look:

    http://kahrtalk.com/showthread.php?t=1368

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  10. #10
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    Quote Originally Posted by wyntrout View Post
    gb6491, I would add that Kahr's "fix" of beveling the "stripper" doesn't move the cartridge, it pushes on the rear of the cartridge and moves the top of the magazine forward while the cartridge remains all the way to the rear of the magazine. I checked and double-checked that. Evidently there is a bit of extra space (or slop) in the top of the magazine well. The bevel and a new ejector seemed to fix everything, including the spent cases being ejected at my forehead. I will wear my Kahr cap every time I go to the range now, as well as shooting glasses.
    Wynn,
    You are correct, though the cartridge moves a very slight amount (at least in my pistol), the movement of the magazine is what makes this modification work. I've edited my earlier post to more accurately reflect this; thanks for bringing it up I must say I was a little relieved to see that Kahr's fix on your gun mirrored what I had done on mine earlier.
    Regards,
    Greg

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