Slide will not lock back

[edhunter]

9/17/09


RE: Slide will not lock back


For some reason the slide on my T9 (s/n PA0244) will, more often than not, not lock back following the final round. I can rack the slide back and it will lock. But it will not lock back on recoil on the final round.

I am using Winchester 9mm 115 gr FMJ cartridges.

Any thoughts?

[Dozer]

Things to check:

Does the slide fail to lock with different ammo?

Does the slide fail to lock with different magazines?

Is the gun really clean?

Is the gun properly lubed?

Does your thumb ride the slide release lever? (more common than you might think!)

[kahrcrazy]

Your slide stop spring may be slightly bent preventing the slide stop from going up and locking the slide back.

[jocko]

Your slide stop spring may be slightly bent preventing the slide stop from going up and locking the slide back.

that can happen. the slide stop spring on the metal series is all together different that what is on the polymer framed guns.

the only thing that activates the slide stop is the follower. U could have weak magazine springs causing it, Your follower just might n0t be pick ing up the slide lever on the inside, but I seriously doubt that.

One common cause is your thumb is in advertainly hitting the slide stop lever enough to prevent engagement.

You might also have some weak recoil springs that is causing the slide to eject rounds but not allowing the follower to pick up the slide lock lever. Timing is all important. If in doubt change recoil springs and then get a new set of magazine springs. I buy my magazine springs off of wolffs (gunsprings.com) and I thinkyou can even order their 5% extra strength magazine springs wich will certainly help with slide lock issues.

By the way wolffs makes kahrs springs to, so u have good ones in your gun, but I would start there first.

If you take your slide off the gun and insert the slide lock lever you will or should see that that slide lock spring located on the inside right side of the frame is always wanting to push the slide stop lever DOWN not up. Only the magazine causes the slide stop to go upward and again timing of the gun is all important in this matter. Normally new springs takes care of it..

[jocko]

dozer: the thumb thing is very common, un knowing to alot also....

[G20-IWB24/7]

No need to buy Wolff springs. Kahr outsources the production of all of their springs to Wolff, so you are already getting the premium springs.

My bet would be the thumb on the slide stop lever. One way to test the theory is to fire 100 rounds left-handed. If the problem stops altogether, you know it was your thumb(s). If not, it might be one of the mechanical issues listed above.

Good luck.

-G20

[ripley16]

One way to test the theory is to fire 100 rounds left-handed.


-G20

Good way to test the thumb theory. My guess too is that it is a roving thumb or a worn follower, provided the slide stop itself is not worn. The slide stop lever piece that catches the slide should be squared, not rounded.

[johnh]

I have seen the thumb problem many times with small auto-loaders. The left handed shooting suggestion is a good one. Gripping lower may be all you need to do.

John

[edhunter]

RE: My original post about the slide not locking back.


Apparently the thumb-issue seems to be a common reply and the suggestion to try left-handed.

Well, I need to do some “weak-hand” shooting so I’ve got an added incentive now.

Thanks.

edhunter

[jocko]

RE: My original post about the slide not locking back.


Apparently the thumb-issue seems to be a common reply and the suggestion to try left-handed.

Well, I need to do some “weak-hand” shooting so I’ve got an added incentive now.

Thanks.

edhunter

lefty''s never have that issue:D:D

[johnh]

I shoot long guns left handed due to cross dominant vision, and you know at times I think left handed shooters do have an edge with some platforms. I chuckle when I see guys fumbling around trying to work the bolt on an AK with their right hand.

:D

On the other hand the G3s I have owned were not so left hand friendly...

John

[Ken S]

If you take your slide off the gun and insert the slide lock lever you will or should see that that slide lock spring located on the inside right side of the frame is always wanting to push the slide stop lever DOWN not up. Only the magazine causes the slide stop to go upward and again timing of the gun is all important in this matter. Normally new springs takes care of it..

The OP mentioned a T9; I recently replaced the slide stop spring on my T40 and I believe they're located on the left side of the frame on all T models.

It's a small-diameter, triangular spring with one end bent to index it in a hole in the frame and is held in place by a Torx screw. The front end of the spring sits in a circumferential groove cut into the left side of the slide stop. When reinserting the slide stop, you have to be very careful that the rear end of the spring rides on the top part of the slide stop.

The slide stop spring on my K9 is located on the right side of the frame. It is considerably thicker and rides in a groove cut on the upper right end of the slide stop. I much prefer this design.

In my case, I ended up replacing the slide stop, slide stop spring and magazine followers.

The metal inserts in the front left corner of the magazine followers were worn to the point that they barely engaged the slide stop. Also, the slide stop spring was not putting sufficient tension on the slide stop to keep it from moving laterally slightly, allowing the slide stop to drop down. Finally, the slide stop was worn to where it did not reliably engage even with the new magazine followers and slide stop spring.

Replacing those three parts corrected the malfunction and now it's back to 100% reliability. :)

[jocko]

The OP mentioned a T9; I recently replaced the slide stop spring on my T40 and I believe they're located on the left side of the frame on all T models.

It's a small-diameter, triangular spring with one end bent to index it in a hole in the frame and is held in place by a Torx screw. The front end of the spring sits in a circumferential groove cut into the left side of the slide stop. When reinserting the slide stop, you have to be very careful that the rear end of the spring rides on the top part of the slide stop.

The slide stop spring on my K9 is located on the right side of the frame. It is considerably thicker and rides in a groove cut on the upper right end of the slide stop. I much prefer this design.

In my case, I ended up replacing the slide stop, slide stop spring and magazine followers.



The metal inserts in the front left corner of the magazine followers were worn to the point that they barely engaged the slide stop. Also, the slide stop spring was not putting sufficient tension on the slide stop to keep it from moving laterally slightly, allowing the slide stop to drop down. Finally, the slide stop was worn to where it did not reliably engage even with the new magazine followers and slide stop spring.

Replacing those three parts corrected the malfunction and now it's back to 100% reliability. :)

I think u might be referring to the TP series and not the T SERIES. the T and K series is the all steel version and the slide stop spring is on the right side inside the frame area. That little springy thing u are referring to is on all the polmer series kahrs.. if ur T series has the left side springy thing, indeed it is a very very early model, and it would be the first I have ever heard of that way....

[Ken S]

I think u might be referring to the TP series and not the T SERIES. the T and K series is the all steel version and the slide stop spring is on the right side inside the frame area. That little springy thing u are referring to is on all the polmer series kahrs.. if ur T series has the left side springy thing, indeed it is a very very early model, and it would be the first I have ever heard of that way....

I'm not sure of its age as I bought it used but mine is definitely an all-steel T40, not a TP series. Interestingly, Kahr shows the small, triangular slide stop spring in their exploded views of both the T40 and MK9 on their website (in the parts section).

I have a K9 which has the stouter spring on the right side of the frame and I love that setup. My MK9 also has the goofy triangular spring.

So two of my three all-steel versions have the small triangular spring. :(

[jocko]

u can callkahr and get a birth date on that T40. I think this fourm has kahr serial numbers history that should get you within a few months of production. That is a new one on me, thanks for updating that. Indeed the right side set up is much better and stronger also. Can't abuse it like that little springy thing on the right..

[at_liberty]

Well, here's another view, because I have both the T9 and T40 and am experiencing chronic problems with the T40, which rarely hangs open after the final round. It is a new problem.

I have disassembled and cleaned magazines. I have three and all of them give the same problem. The thumb on the release is a possibility, but I NEVER have the problem on the T9.

In comparing T9 and T40 magazines, I notice that the metal tip that catches (sorry for not knowing the right term) is a different style. The T9 magazines show no wear, but the T40 mags are all torn up. The mating part on the gun shows wear too, but not as bad, probably much harder material.

I plan to order new mags and new +5% springs in an effort to salvage what I have, but I think I really need new plastic pieces in the magazines to get unworn "catches". The slide lock is probably toast as well.

Both guns have been thoroughly cleaned at the same time and in the same way. I just did a course on Handgun maintenance and have also reviewed the manuals, hard copy and online. I have cleaned magazines but have not tried them yet. They were not dirty particularly.

I am considering having the factory guys look at it, because my logic tells me the gun is chewing up magazines..

[jocko]

If it was my gun I would at least first replce the magazine springs. A strong indication of what causes the last round in a magazine to lock open the slide is a weak magazine spring expecially on the last round where all the compression is now gone and what is happening the slide is moving faster than the follower can pick up that slide lock lever and lock the slide open. It is not your slide lock lever. If you gonna try this ten also just replce the recoil springs at the same time. between these two, my bet it iwlls ove your issue.

If you go to gunsprings.com (wolffs) they make a 22# recoil spring for your gun, your factory spring is 20#. IMO this helps the gun alot the K and t series take the same recoil springs, and if you go further down on their list of magazine springs, they also make a 5% extra power magazine spring which really helps that last round stuff alot. You wo['t notice any difference in loading the magazine with the 5% extra strength magazine spring but IMO it certainly cannot hurt one thing. Wolffs makes great springs, they also do extensive testing of heavier poundage springs to. I have found in all my kahrs if I step up to the next poundage of recoil springs that wolffs offer, the the over all life of the recoil springs is much longer. racking a 20# vs 22# recoil spring in a T9 is a no brainer also.

If the gun failed to lock open msot of the I would think something else could be wrong but your stating towards the last round and to me that is a real indication of weak magazine springs FIRST.

[at_liberty]

It just occurred to me that I was in the habit of closing the breech on the next magazine using the slide lock release (one handed). That would tend to round off corners, I think, but the T9 catch is already rounded like a dome to allow that, no problem. At least with range use, I will close the breech manually on the T40 to reduce wear. With magnification I can see that the T40 mags clearly rely on a squared surface. Maybe the new springs will get better engagement quicker and reduce that rounding over. I still think I need to start over with new "catches" on the mags. I am not aware the plastic parts can be bought separately...bummer.

Yes, I will try new springs on the old mags. I appreciate the tips.

[wyntrout]

It just occurred to me that I was in the habit of closing the breech on the next magazine using the slide lock release (one handed). That would tend to round off corners, I think, but the T9 catch is already rounded like a dome to allow that, no problem. At least with range use, I will close the breech manually on the T40 to reduce wear. With magnification I can see that the T40 mags clearly rely on a squared surface. Maybe the new springs will get better engagement quicker and reduce that rounding over. I still think I need to start over with new "catches" on the mags. I am not aware the plastic parts can be bought separately...bummer.

Yes, I will get a try new springs on the old mags. I appreciate the tips.

Yes, look at the parts page at Kahr.com. They offer magazine kits with a new spring and follower for less than half the cost of a new magazine. The shipping on the first $50 is $6 and only a few bucks more if you go over $50.
KAHR ARMS ONLINE SHOP (http://www.kahrshop.com/)
select Accessories and look at Magazine Maintenance Kits. $19 each.
You may need a slide realease lever and you can get some of this stuff sent as warranty self-repairs for free. Others can tell you about this.
Goodluck.
Wynn:)

[jocko]

u should use the slide lock lever to load the first round. Every kahr manual states to do this. Now if u can rack with ease and have no issues that is okay, your really not being any kinder to the magazines IMO. use the slide lock lever to load that first round, it willbe consistant every time.

You can buy polymer followers separtely but the best buy is what Wynn stated, buy the maintenance mag kits. Then u know you have done it allright in that area anyways..

[at_liberty]

I have ordered springs and new follower inserts but in the meantime discovered that the screw that secures the little spring that operates the slide lock was slightly loose. I degreased that area and snugged up the screw and am now getting the slide locking every time I pull it back with a cleaned and degreased empty mag, despite the wear. I think the unusual wear that has occurred in the meantime has indeed ruined both mating surfaces, follower and slide lock. I have ordered the followers but now plan to order a new slide lock. It's pretty chewed up for all those near misses and failure to catch on the follower.

I guess I should ask about use of LocTite on the threads of that little screw. All I have is the mild hold version for little stuff like eyeglasses. I have no idea how cleaning would affect it. Any thoughts?