solved premature slide lock for good

[olympicmotorcars]

I got my PM 40 back from the second visit to Kahr this week. Looks like the broken follower problem may be solved, but it is still having premature slide lock with my gold dot 165 grain carry ammo.

The nose of the bullet is brushing against the slide lock lever. I have put the lever back on the disassembled frame and inserted the magazine to check it several times. I have tried multiple times to file the lever down so that it clears the nose of the bullet, but just could not ever get it to clear those big hollow points.

It doesn't happen every time, but my luck would be it would happen at the worst time when I really needed my gun. so............

I finally just completely ground down the lever flush so that it will not even lock back on an empty magazine. A lot of smaller guns on the market do not lock open on an empty magazine, and I decided I could live with this . I do not carry an extra magazine , so if I ever needed a tactical reload I would be up the creek anyway.

Not really an ideal fix but really do not know anything else to do. The tolerances on the lever seem incredibly slim between working correctly and not working correctly.

I have an extra slide lock lever if I ever decide I want it back like it was.

I may should have tried another type of ammo, but gold dots work perfect in all my other guns, and up until this year my Kahr was running 100 percent with them.

One other thing I have noticed recently . I changed recoil spring assemblies several months ago and noticed my guide rods are getting dented in the middle of them. I cannot understand why.

I am getting somewhat discouraged. I have been carrying my Walther PPS the last several months until I could get my PM 40 working 100 percent. I need to go to the range a few more times until I can trust it again.

I have been thinking about buying a larger gun ( either a P40 or K40 ). I must admit I am having second thoughts now.

[garyb]

I'd be discouraged too and would think twice about another one. I guess you gotta do what you gotta do. However, I'd be trying some other ammo or whatever needed to be done to get it running correctly. As for your guide rod, hope you are putting some grease on them so the springs glide smoothly? Did you compare the old recoil spring assembly to the new one to be certain it was a direct match replacement?


The PM40 is certainly capable of running like a champ. Mine has always been flawless for me and I would try my very best to get things straightened out if I had a problem with it. Leaving it with problems would continue to drive me nuts. Best of luck with it. Merry Christmas.

[muggsy]

It would seem to me that the simple solution to your problem would be to choose a cartridge with a projectile ogive configuration that would clear the slide stop. For the benefit of Jocko, that's means that you should find a hollow point bullet that will work in your gun.

[jocko]

try anutter brand of ammo. lots of great 40 cal ammo out there. MYP380 would not feed 102 grain golden sabre, I just changted ammo that work3ed perfect. Certainly can't always blame the gun for what a ammo maker makes either.

the dent in the guide rod-- is it causing any issues???? If it ain't broke don't fix it.

[scosgt]

The REAL solution to the PSL problem is
DEGREASE THE INSIDE OF THE MAGAZINES

I had this problem with an MK-9, and then with my CM40 when I first got it.
Yes, the round is hitting the SL, but the REASON is that the mags come wet with oil. This allows rounds to slide forward on recoil, magnifying the problem. If you completely remove all oil from the inside of the mags, a slight polish on the SL should solve the problem for good.

[olympicmotorcars]

Hey Garyb, what ammo are you using in yours?

[harzer]

I have the same problem in my cw380. It runs fine with Horn.critical def.conical tip and will go every single time in slide lock with fmj round nose or open hollow points. I noticed,that the round slides forward in the mag. Any help to fix this issue is greatly appreciated

[scosgt]

i have the same problem in my cw380. It runs fine with horn.critical def.conical tip and will go every single time in slide lock with fmj round nose or open hollow points. I noticed,that the round slides forward in the mag. Any help to fix this issue is greatly appreciated


degrease the insides of the mags.

[JERRY]

im ok with this "fix".


a revolver has no slide lock when its out of ammo and it reloads just fine.


so does a LWS.

[garyb]

Hey Garyb, what ammo are you using in yours?



I reload for the range. For SD I found inexpensive Win T's do the job. Bought two 50 rd boxes that I tried out to be certain they cycle....and now I keep them for SD only. They are the same as the Win PDX which are bonded. The Win T's are not bonded. They were the black talons which were discontinued for racial reasons.


I also degreased and waxed my mags inside and out. I use a good hard floor PASTE wax. It is an old solution we wood workers use on their table saws tables, band saws, planer tables, etc.... anyplace the wood needs to slide nice and smooth. It protects the surface by sealing the pores in the metal and it creates a clean, grease free slick surface. The waxed surface holds up for a long time. You might want to try it. These other guys may just be on to something and if that works for you it is a pretty easy fix.

[scosgt]

I reload for the range. For SD I found inexpensive Win T's do the job. Bought two 50 rd boxes that I tried out to be certain they cycle....and now I keep them for SD only. They are the same as the Win PDX which are bonded. The Win T's are not bonded. They were the black talons which were discontinued for racial reasons.


I also degreased and waxed my mags inside and out. I use a good hard floor PASTE wax. It is an old solution we wood workers use on their table saws tables, band saws, planer tables, etc.... anyplace the wood needs to slide nice and smooth. It protects the surface by sealing the pores in the metal and it creates a clean, grease free slick surface. The waxed surface holds up for a long time. You might want to try it. These other guys may just be on to something and if that works for you it is a pretty easy fix.

Do NOT wax the inside of the mags. You do NOT want them slippery, it allows the rounds to slide forward under recoil and contact the SL on the way up.
Degrease degrease degrease.

[garyb]

Do NOT wax the inside of the mags. You do NOT want them slippery, it allows the rounds to slide forward under recoil and contact the SL on the way up.
Degrease degrease degrease.



I don't know where you learned this and won't say you are right or wrong. However, I've been successfully shooting my PM40 with the mags waxed inside and out for years without any failures of any kind. I did NOT wax the follower's bullet contact surface. That is the only surface that would allow the bullet to slide forward under recoil. Soooo, everything is working well the way I waxed things. Wax on the mag inside and out, mag spring. No wax on the follower. Works without failures.


One more point - When you apply the paste wax, apply a very thin coat and remove it with a clean dry rag after about 10 minutes. Then apply a 2nd thin application, wait 10 min and wipe it back down. Finally, repeat with a 3rd application. This seals the metal pores, but does not leave any wet wax residue. The objective is to leave everything dry but slick....EXCEPT the follower.

[scosgt]

You do NOT want the inside of the mags slick. This is a big mistake and will lead to PSL on some guns.
MINE was cured by degreasing the inside of the mags. If the next round is allowed to slide forward under recoil it can strike the SL causing PSL.

[warbird1]

Corbon Pow'RBall.....for the easy solution.

[scosgt]

Corbon Pow'RBall.....for the easy solution.

No, my MK-9 did PSL at least once in every mag, no matter what ammo I used and no matter that I ground down the stud a lot.

I gave up and traded it in.

When I first got the CM40, it did the same thing 3 times in 200 rounds.

Then I used Gunscubber inside the mags and got them really dry, never a failure since then.

The 9mm mags were oiled from the factory, and I do recall cleaning and oiling them.

You can easily see this yourself. Mount the barrel to the slide with the SL and put in a mag. In fact, don't bother with the barrel. You can see that if the round comes forward just a bit the fatter part of the bullet smacks the SL. SO preventing the round from coming forward is one cure.

[olympicmotorcars]

No, my MK-9 did PSL at least once in every mag, no matter what ammo I used and no matter that I ground down the stud a lot.

I gave up and traded it in.

When I first got the CM40, it did the same thing 3 times in 200 rounds.

Then I used Gunscubber inside the mags and got them really dry, never a failure since then.

The 9mm mags were oiled from the factory, and I do recall cleaning and oiling them.

You can easily see this yourself. Mount the barrel to the slide with the SL and put in a mag. In fact, don't bother with the barrel. You can see that if the round comes forward just a bit the fatter part of the bullet smacks the SL. SO preventing the round from coming forward is one cure.

I can understand that the dry magazine will probably help with enough friction to keep the round from going forward , but I am uncomfortable with any configuration that will allow a round ( under any circumstances ) to contact the slide lock.

It would be my luck that when I really needed my weapon , a drop of errant lube would have found its way into just the right spot and the round would slide forward and lock it up.

I may eventually get some Hornady critical duty and try them with my other slide lock, but for right now I am satisfied with this solution.

[gb6491]

Just my two cents:
My CW45 would intermittently lock the slide back with rounds still in the magazine.
What remedied this for me was tightening the slide stop spring screw:
http://www.kahrtalk.com/showpost.php?p=15672&postcount=5
Regards,
Greg

[JimC]

Clean and dry inside of any semi-auto pistol mag has worked just fine for me for over 45 years. I'll skip all the other suggestions, including "waxing"...:rolleyes:

[harzer]

I cleaned the mags of the cw380 with degreaser in and out, filed and polished the slide stop and it is still doing it with both mags on round nose bullets only. Kind of aggravating.I have the cw45,cw40 and pm9 none of them has a problem.

[olympicmotorcars]

That is a very interesting thought GB6491. I may play with the slide stop spring some if I get brave. I have always been afraid to touch it in the past after reading the posts about stripping out the threads in the polymer.

[Schriscoe]

Good info here guys. I just bought a CM9 and was getting discouraged by premature slide locking. It had only happened with +p 124 gold dots and 147 JHP loads. Not with 115 of any kind. I've got some things to try now. It's fun to shoot otherwise, just not quite as fun as my XDs 45. But the Kahr is lighter.

[garyb]

You do NOT want the inside of the mags slick. This is a big mistake and will lead to PSL on some guns.
MINE was cured by degreasing the inside of the mags. If the next round is allowed to slide forward under recoil it can strike the SL causing PSL.



"On some guns"? Really? Which ones? There are wax based products out there specifically for guns. Nothing new.....been around for many years. For example...."Blue Wonder Armadillo" - states right on the packaging...."Dry Lube for Slides and Magazines"....Hmmmm. Gun wax is not a new method for gun lube and protectant. It has been around for a LONG time. Waxing as I described worked just fine on my PM's 5 mags. You'd think if there was a problem it would have showed up over the last few years. Curious as to what source your info came from as to waxing the mag will cause PSL and specifically on which guns? Interesting.

[scosgt]

"On some guns"? Really? Which ones? There are wax based products out there specifically for guns. Nothing new.....been around for many years. For example...."Blue Wonder Armadillo" - states right on the packaging...."Dry Lube for Slides and Magazines"....Hmmmm. Gun wax is not a new method for gun lube and protectant. It has been around for a LONG time. Waxing as I described worked just fine on my PM's 5 mags. You'd think if there was a problem it would have showed up over the last few years. Curious as to what source your info came from as to waxing the mag will cause PSL and specifically on which guns? Interesting.

I think I made it clear that the PSL problem on my two Kahrs was traced to oil inside the mags allowing the rounds to slide forward under recoil and therefore be able to hit the SL on the way up.

Now go wax whatever you want.

[garyb]

I had hoped you might provide some references against using wax. I had a sincere interest in your comment and thought maybe you were on to something. Therefore, I did a little more research on the mag cleaning and lube issue. Several references referred to using gun wax products including: Flitz Rifle/Gun Wax; R. Gail Lock Co. Carnuba Gun Wax # 36; some use certain auto wax products; and Johnson's Floor Paste wax. Specifically described was to do the spring, inside and outside of the mag. Benefits include preventing rust and wear. Most significant is that buffed out wax does not attract dust or dirt. Still others (ie., www.Xavierthoughts.blogspot.com (http://www.Xavierthoughts.blogspot.com) recommends powdered graphite for mag followers and spring. Some recommend dry lube/rust inhibitor like Eezox. Finally, some do use very light coat of oil, but wipe it out because it does attract dust and dirt, particularly if dropping mags to the dirt during competition....makes sense.

YES, it was clear that you had problems with oil inside your mags and perhaps they were not cleaned well....but that is oil, NOT buffed out wax...and wax on the mag...NOT the follower. Wax stays put and won't migrate to the follower/bullet surface. Could be that oil from your mag got on your follower surface and allowed the rounds to slide? I don't know, but the info you provided did not relate to wax on the inside surface of the mag. The info related to lube on the follower.



Other than yours, it seems to me that there are NO references that clearly speak against using wax on mags. In fact, it appears that wax may be one of the best products for both the outside and inside of mags and springs (not followers). It protects the surfaces, provides dry lubrication and does not attract dust and dirt. There are gun wax products available on the market but several references successfully use Johnson's Floor paste wax just as I do.

As an aside, another thing I learned is that some recommend against using very light oil for two reasons: 1. It attracts dust and dirt, particularly if mags are dropped in the dirt....This makes perfect sense...hence use wax or graphite. 2. Oil will kill primers. However, www.thetruth.com (http://www.thetruth.com) did an extensive test on primed ammo and found that the assumption that oil will kill loaded ammo primers is totally FALSE. The test soaked the primer in oil and the ammo fired just fine. The article specifically stated that light oil wiped down on the inside of mags is not nearly enough to affect the primer of loaded ammo.

That's my research....but we are getting off the OP's thread a bit so I'll let it go at that.

[scosgt]

PSL is a known and documented issue on the small Kahr guns.
I told you what I found that cured it - simply degrease the inside of the mags.

You have waxed on about wax. Wax whatever you want.

Anyone with PSL issues on a Kahr should completely remove all oil from the inside of the mags. The added friction on the rounds helps prevent them from sliding forward under recoil.

[garyb]

Do NOT wax the inside of the mags. You do NOT want them slippery, it allows the rounds to slide forward under recoil and contact the SL on the way up.
Degrease degrease degrease.

Calm down. Just a dialog providing additional references about your comment.

[yqtszhj]

Just my two cents:
My CW45 would intermittently lock the slide back with rounds still in the magazine.
What remedied this for me was tightening the slide stop spring screw:
http://www.kahrtalk.com/showpost.php?p=15672&postcount=5
Regards,
Greg

That's what I was thinking too. Especially if you still get the slide lock problem now after your mod.

[muggsy]

Calm down. Just a dialog providing additional references about your comment.

Gary, I think that you waxed eloquently on this issue. Just because degreasing cured the problem on one gun doesn't necessarily that it will cure the problem on all guns. Not only do I wax my mags, but I deburred the feed lips as well and have never experienced premature slide lock.

[Schriscoe]

I have decided my gun is just a bit ammo finicky. Speer gold dot 124 +p and WWB 147 JHP both seem to elicit premature slide lock mid magazine. I'm now about 300 rounds into my CM9 and this seems to be consistent. I just function tested shooting 1 handed to rule out thumbing the slide lever, and got my 1 slide lock malfunction with the 147s. Then got one FTF with 124 +p golden sabers. So far, Hornady Zmax and hornady critical duty 135 seem to run fine. I'll be carrying critical duty, got a great deal on some 50 round boxes so I'm thrilled the little Kahr likes it.