Occassional FTF

[jfrey]

I have over 1000 rounds through my CW9 and still have a FTF once in a while. Shot 40 rounds through it today and the third round in the second mag didn't go off. Reset the striker and it went off the second time. The striker sounds weak when this happens. Problem is that you never know when this is going to happen so it raises issues considering this as a carry gun. The striker channel and parts are cleaned regularly and gun is lubed properly and striker spring has been replaced.

Anyone else have this occassional problem with any Kahr models?

jfrey

[jocko]

when you get this FTF, eject the round and look at the bullet closely. If there are marks on the bullet, it could be that that round is hitting the throated area of the barrel and actually putting the slide ot of time. your issue is so isolated tha tit is going to be hard to catch even, so you hav eto try to eliminate any possables that might be causing it. keep a eye on which brand of ammo is doing ithis, or is it with all ammo, or certaind efense rounds etc . Before you call kahr with your issue, you need to be able to tellthem what you have tried to do to eliminate this issue ...There has been some very good tips put forth here lately about where to look for maybe things that are not correct...

gkstemple related an issue with his c45 with the trigger bar not resetting due to some excess flashing left on thepolymer frame. That was anew one to me even but it sure made alot of sense and he sure figured it out to by traial and erro. You might wantto look had in that area to. I always put a dab of greast on that ear on that trigger bar and behind that ear even.

Again before you call kahr try to eliminate any possables that have been brought forward on this forum.

[ripley16]

By FTF, I assume you mean "fail to fire" due to a light strike. My CW9 did this. I tried changing striker springs but that didn't help. I suspect the striker itself was the cause... maybe a bit too short. The only other cause I could think of was a chamber cut too deep. Unfortunately, I sold the gun without ever solving the problem. However, I suggest you try th cheapest fix first, a new spring and new striker. Because you are over 1000 rounds you may want to replace the recoil spring too. I hope you fix thie problem. It can be very disconcerting to experiencethis in a CCW, even once.

[Bawanna]

Your about due for a recoil spring which is a pretty cheap thing to try. I suspect that as Jocko mentioned perhaps that bullet was a tad long, the first trip. When you retried it the bullet was pushed down just enough so it worked the second time. Just a wild guess.
I know guys that test every single carry round they put in their guns and perhaps thats something I should be doing too. Modern ammo is made pretty darn good but maybe a few leave not quite right.

[jocko]

but before we blame the gun, we must also check things out beyond that. bullets to long will cause issues, old worn recoiil springs don't help a damn bit either. improper luberication. shooter error also. these are all things that have zero to do with the guns reliability. I no doubt would have to agree with Bawanna (kills me to do that as he gets so big headed over it) but my primary carry magazine and one in the pipe should all be pre tested rounds for propper feeding. I am guilty of not doing that, actually never thought about it until the ol wise one suggested it. I am now doing that as I type. We are never to old to learn...

I can live with a bad round when doing range time but again one must eliminate all the possables that can cause a malfunction, and then as we all know sh-t can still happen

[ripley16]

I don't get some of the replies. What do recoil springs, trigger bars, round length, etc have to do with light strikes? :confused:

Hard primers? Maybe.
Old ammo? Maybe.
Boken striker? Maybe.

Lubrication? Probably not.
Recoil spring? No.
Long ammo? That causes other problems. :31:

Maybe I had too much Egg Nog over the weekend, but I don't understand your answers and how they relate to Jfrey's problem.
:001_huh:
Enlighten me.

[Bawanna]

Quite often a light strike can be attributed to the gun being slightly out of battery. Not enough to stop it from firing but enough to slow down the striker.
The recoil spring if weak might not slam the slide forward with quite enough gusto to get all the way home. You may not even notice it. Usually a slight smack on the back if you do notice will put it in battery, if you even notice.

Lack of lube can contribute the same way if the gun is a bit tight or other things are slowing things down too.

Hard primers could certainly be a factor but any Kahr or any gun thats working properly should bust even the hardest primers.
I'd not be to concerned about old ammo unless its just not got enough stuff to cycle things good enough. A light reload would certainly be a factor.

A broken striker would certainly do it, although any I've seen broken broke far enough back that there was no strike at all, not a light strike. I've not encountered any that were significantly worn to cause a problem but that would do it if it ever happened.

The trigger bar has been a cause to several here in the past, apparently not allowing the striker to move at the proper time or velocity.

The round length if too long just doesn't allow the slide to go fully into battery, maybe close enough and I'd say 9 times out of 10 it would still fire, my K40 did that in it's early days. Add a couple other factors like a dry gun, or weak springs and once in awhile you'll have a failure.

Least ways, this is my thinking, much as thinking is painful for me.

[jocko]

I don't get some of the replies. What do recoil springs, trigger bars, round length, etc have to do with light strikes? :confused:

Hard primers? Maybe.
Old ammo? Maybe.
Boken striker? Maybe.

Lubrication? Probably not.
Recoil spring? No.
Long ammo? That causes other problems. :31:

Maybe I had too much Egg Nog over the weekend, but I don't understand your answers and how they relate to Jfrey's problem.
:001_huh:
Enlighten me.

all about the timeing of thegun and any one of those 3 can cause improper timing, therefore light strikes are part of the issues from that to. I think we blame ammo makers to much for hard primers. They know better than to do that, sure if u take allof the ammo makers and test all their primers, your gonna have a scale of them from harder to softer but the harder ones willnot hinder a gun operating right. These ammo makes certainly know how to make ammo and it would certainly be to no avail to make hard primers an issue with thier ammo eitehr.

I think bawanna answered most of the questions correctly IMO..

[jocko]

might not had been a hard primer as maybe a bad anvil not seated correctlty. They crank those things out by the billions, amazing we don't have more issues with primers and even bullets being seated to far out..

[jfrey]

I'm gonna run through a quick checkoff list: old ammo - no, lack of lube - no, hard primer - probably not, broken striker - no. That leaves recoil spring and long ammo. I'll replace the recoil spring, as I have spares. Long ammo - possily. I measured the OAL of about dozen rounds in same box and found 1 that was longer than the others. Not a lot, but definately longer. I think five thousandths or so could be just long enough to cause a problem if they are all setting right against the rifling otherwise. I shot some Cor-bon loads and nary a problem. Seems I get this with range ammo which is lighter loading.

Seems that someone, possibly Bawanna or Jocko, said a while back that Kahrs like a little hotter ammo anyway.

Thanks for the replies. Gonna go check some more ammo for long rounds.

[Bawanna]

I can attest that 5/1000's is more than enough to tie a gun up. This is what I had with my reloads not long ago. I went strictly on book OAL and they just flat were too long. I had to do the dowel down the barrel and drive the bullet out of the rifling to get the gun open. Frustrating as heck.
I don't think I was even 5/1000's too long, less than that.
We're just eliminating ammo concerns here too, not saying there might not be another issue, just a possibility that the ammo is a cause.
I still think that Kahrs are generally not ammo sensitive and they should run everything except maybe Wolf or Magtech and who wants to shoot that stuff anyhow. (my personal opinion disclaimer).

[Bawanna]

Even better than measuring is just take the barrel out of your gun and put rounds in the chamber and push them in hard with your thumb. Then flip the barrel up chamber down and it should just fall out with no effort at all. If it hangs even a bit its too long or otherwise out of spec in some way.

At Tilos and others suggestion I now do that with random rounds that I reload. I've done this before but didn't push the round in, just let it drop, that little push is enough to force the bullet into the lands and make bad things happen.

[OldLincoln]

I think Bawanna is right and here's why:

Please correct the following if I'm wrong....

The spring on the striker takes it so far and the rest is inertia.* Light strikes don't have the inertia to pop the primer. The new spring should rule out the inertia factor and cleaning the channel rules out obstructions. Note he replaced the spring so it's remove and replace the striker not only the brake cleaner routine. If new spring rules out the inertia factor, then it's a matter of the breach (therefore the round) being out of position in relation to the striker.

The striker can be released ever so slightly before the slide is fully forward.** I suppose in rapid fire it could be coincidental to release the striker before the slide goes home but I doubt it. In slow fire a round could hang on the ramp just enough to mess it up but I would expect Fail to Chamber or Load or Feed (whatever they call it). Let's put it this way, if the slide is not fully closing on a good round then I suspect a dirty or improperly lubed action, the ramp being gunked up, a weak recoil spring, and/or a weak mag spring. jfrey cleans and lubes the gun so I'm setting the clean and lubed issue aside. If the ramp is shiny when cleaned, I'll rule that out as 40 rounds should not mess it up that bad (although I do occasionally wipe the ramp when reloading mags).

That sorta points to a weak recoil spring and/or mag spring. Both relate to timing as Jocko mentioned. I'm still learning but I had the issue on my 1911, so I'll give it a shot

As the slide moves forward it scrapes the top round off the mag. It is important that the top round be held in place by the mag spring pushing it against the mag lips until released by the lips at the proper time.

The round is pushed along into the ramp. Here a polished ramp reduces friction and allows it to slide upward easier. But a non-polished gunky ramp accompanied by a weak recoil spring will allow it to nose dive and hang on some ammo. A strong spring pops it up the ramp toward the chamber.

The round is at a pretty steep angle with the bullet riding the inside top of the chamber (polish that also) when it is released from the mag and the base snaps up under the extractor. The angle is now straight, the round aligned as the slide rams it home.***

There is a lot happening that depends on a strong mag spring and strong recoil spring. Recall when your Kahr was new. Were the mags stiff to load by hand? How about slingshot the slide? They are stiff for a reason, not just because it's new.

As the gun wears in the action becomes smoother and we like it better - a good thing. But when the springs get mushy they need replacing. We call it by the failures that are symptoms (Fail to Feed, Chamber, Load, Fire, Stove pipe, etc.) but the cause is often timing and means it's time to replace springs, check mag lips (they can spread and release the round too soon). Bottom line is the mag and slide have to work in sync or you have problems.

So, I'll echo replacing the recoil spring as number one. But, if the mags don't hurt your fingers to reload, replace mag springs also.

NOTES:
* You can see this looking at the slide. Press the striker block and the striker just sits there until you move it. Pull it back and you can see where the spring get involved.

** With an EMPTY gun, the striker set and slide closed, gently push the slide back while fingering the trigger. You can feel the trigger resistance even when the top of the barrel moves ever so slightly out of position. Move further and the trigger moves freely.

*** You can see the activity by removing the recoil spring only, insert a loaded mag, POINT the gun to a safe area and CAREFULLY work the slide back then push it forward. You can see what I described above only the round will probably lodge into the ramp (you are the recoil spring). You can get a FMJ to come free but you only want it a little free. Watch to see how the round comes off the mag. It should not release until the extractor is above it. It will pop out of the mag out of control, but if you gently hold the forward part with a finger, it should pop under the extractor. Pushing further you can see how the round makes it into the chamber. PLEASE - at this point remove the mag and the chambered round. IT IS A LIVE ROUND AND CAN BE FIRED!

This exercise demonstrates the feed action. Also, while totally unloaded and recoil spring removed, you can put some pressure on the barrel and see how the locked breach action works. It really helps to understand these things as you put the gun to use.

[jfrey]

I installed a new recoil spring and noticed the one I took out was about 2-2 1/2 coils shorter than the new one. Speer book shows 1.135 OAL for round nose 115 gr bullets. I was loading at approx. 1.140 +-. I'm going to push 'em down to 1.135 to 1.132 and that should do better. Same rounds haven't been a problem in several other 9mm's but different brands of guns. The longest round I measured was 1.1425 and as Jocko sad that could be the culprit.

Thanks for all the advise. Youguys are great help.
jfrey