CM40 question

[robert3409]

I have a CM40 that is a little over a year old. It has been flawless for around 1,000 rounds. I carry the pistol off duty and lately I noticed the slide will not lock back on an empty magazine. The gun is cleaned regularly and I've taken the magazine apart and noticed at first the gun will lock back but the slide lock is barely being pushed up enough by the magazine follower to catch the slide. I ordered a new magazine spring yesterday. What do you guys think?

[jocko]

goodplace to start but maybe that little slide lock springis inneed of adjustment. U might have bentin during some re=assembly.

U can go to wollfs guns springs and they make a 5% more strength mag spring for yoiuyr kahr. Also check to see if the metal tabon that magazinefollower is OK. Does it lock open when firing it on the last round??? Maybe a new outter recoil spring would bein order also, as it is allabout tiing with a semi. All things need to be right. U can order the outter recoil spring from wolffs for ur cm40 to if u go to their website and order the PM9 / 40 outter recoil spring, That is the only part u need to change.

IMO if it has worked OK for a 1000 rounds and now is acting up. that is a good indication of SPRINGS. There is a nice photo tutorial on the kahr tech section by Wyn showing how that slide lock spring should look like when it is correct, and also in the klahr prepp section on how to adjust and how to look to see and feel it if is OK.:amflag:

[muggsy]

Did you check for a broken follower before you sent for the mag spring? Did you disassemble and clean the mag? Try both. You might also stretch out that mag spring a bit to see if that helps. If you left the mag fully loaded for a long time the spring may have taken a set.

[robert3409]

Did you check for a broken follower before you sent for the mag spring? Did you disassemble and clean the mag? Try both. You might also stretch out that mag spring a bit to see if that helps. If you left the mag fully loaded for a long time the spring may have taken a set.



I checked the follower. The pistol will hand cycle all 6 rounds (5+1) but it will not lock back when the mag is empty. I've taken the mag apart and cleaned every thing. I admit the magazine is loaded 100% of the time with Winchester Ranger 180gr HP.

[Glock23]

Will it lock back if you manually rack it on an empty mag?

[getsome]

Hi Robert3409, Welcome to Kahrtalk....Replacing mag and recoil springs is the first thing to do although at 1000 rounds they should still have some service life left but new springs is a good idea and cheap insurance...

Not sure about the lock back thing...Are you pulling the slide back by hand on an empty magazine or is the pistol not locking back after you fire the last round?...Big difference between the violent rearward slide movement after a round is fired and the gentle pull back done by hand...If the gun will lock back after the last round in the magazine is fired then I wouldn't worry about it but if not then the mag spring change could only help...

The other thing to look at is to be sure the slide lock spring hasn't gotten bent out of shape during reassembly and if so you can tweak it with a pair of small needle nose pliers....be sure the #6 torx screw is snug but DON'T overtighten it which can strip the polymer...

Lots of people get a new semi auto pistol especially a Kahr since they are so small and tight when new and think there's something wrong with it because they can't make it cycle by using their hand but the gun is designed to operate under extreme force and slide speed which can't be done any other way than by live fire...

Change out the springs and go shoot it then call us back and let us know how it goes....Good luck.....

[jocko]

take the slide off, and reinsert the slide lock lever, now insert an empty mag andlook at that left sife and see if that follower is grabbing that slide lock lever and pushing it upward..

[robert3409]

Will it lock back if you manually rack it on an empty mag?

No that's what I posted above . It will not lock back on an empty magazine. Occasionally it will but the slide lock is barely catching the slide. For some reason the slide lock isn't being pushed up enough by the follower.

[robert3409]

And with all due respect I know how a semi auto works as I've carried and shot dozens in my career.

[robert3409]

I'm high bidder on an M&P shield online just in case. Not flaming or trolling I love this Kahr

[robert3409]

I stretched the spring and it works fine now. I was trying to get a rise out of you guys but nobody would bite. Hahaha

[RRP]

I was trying to get a rise out of you guys but nobody would bite. Hahaha

You mean trolling really does occur on web forums?

[robert3409]

You mean trolling really does occur on web forums?



I read that somewhere..............

[jocko]

never on this forum. Wehave some darn good TROLL mods..:Amflag2:

[muggsy]

Bob, this is a very minor problem and should be relatively easy to fix. Call Kahr Service, explain the problem and ask them how to proceed. If they request that you return the gun for service ask them to email you a prepaid mailing label. If they balk, send it back to Kahr via your local FFL to save yourself some money on shipping costs. It could be something as minor as replacing the mag catch. Regardless, Kahr will repair your gun.