[Capp]

I think I've found it...'least for "my" pistol anyway.

the stoppage;
FTExtract.
Classic case of ext'r hook not yanking the spent case out .
with several factory ammo's

Inpection and evaluation;
Field stripped , removed barrel .
visual inspection showed nothing out of the ordinary .
Slipping a rnd up the breach face and under the ext'r hook revealed NO ext'r grip on the case rim.
Plenty side to side slop as a matter of fact...maybe .010 or beter.
Manually pushing on ext'r (at the ext'r spring's pressure point) changed case grip (or lack of) only slightly

My armorer's knowledge of other pistol platforms set me to diagnosing what was out of spec.
I determined it could only be one or all of three things..

Note the arrows in this pic.
from left to right, we'll call them arrows 1, 2 and 3.
The problem had to be either;

1.) the ext'r is too thick where it rests in the slide channel
2.) the slide channel wasn't milled deep enough
3.) the breach face channel was milled to wide

since putting metal on point 3 isn't an option, and cutting the slide channel deeper with hand tools is foolish..and ever MORE foolish to attempt it with dremel, the wisest move was to remove material from the ext'r.
Not to mention, whenever filing/cutting is needed, always file on the least expensive part first


like this....

BTW, that's a safe edge file ....don't want to cut into the hook.
The arrow points to area of material removal .
I removed .007 originally...test fired 200 rnds and had 1 FTE
(before the tuning, i couldn't get more than 1 in a row to extract)
I knew just a little more material off would finish the tune job

I detail stripped and took another .004 off.
re-assembled ext'r and spring and it held a rnd snugly .
To be sure it wasn't "too" tight, (which can cause Failure to return to battery) I fully assembled and cycled rnds by hand .
Both fast and slow...even did a big no-no by "riding the slide"
all fed 100%
...I'm as happy as pig in chit now



I went ahead an Militec'd the slide
(I Militec every pistol I intend to keep)


fresh out the oven

grease the rails, re-assemble, she's ready for the dance

t



he above tuning may or may not cure "your" extraction ills .
But it was certainly better than adding a second spring ..which would of only helped minimally...and just been a band-aid in reality .... not a cure .

I believe I've "cured" this out of spec pistol


..L.T.A.

 

[mojo-62]

EXCELLENT POST!! I am on this tomorrow. Thanks

 

[pocketdrummer]

I'm glad to hear it!

I have two questions for you...

First, what is the width of the extractor now that you've removed material from it? Perhaps a numerical value would be of worth.

Second, did you have any issues riding the slide? My PF-9 fails to return to battery if I ride it back (stopping 1/4" away). If I smack the back it goes forward all the way. However, pulling it back and letting it go always works.

 

[frankmako]

sounds like this might be the best way to fix the problem.

 

[Capp]

EXCELLENT POST!! I am on this tomorrow. Thanks

you're more than welcome, Mo

i mentioned in the other thread that i measured some ammo case rims.

WWB had the smallest diameter of .385
Fed had the widest at .3885

what that means to me is, the pistols that will extract Fed, but not WWB 100% reliably are literally just a hair's width from having FTE with Fed ammo

Such a thin margin of error wouldn't make me feel comfort in pistol that may be called on for defense


But I'm anal about reliability in a defense weapon


..L.T.A.

 

[Capp]

I'm glad to hear it!

I have two questions for you...

First, what is the width of the extractor now that you've removed material from it? Perhaps a numerical value would be of worth.

oh man, i wrote them down when i started so i knew how much I was taking off.
but I can't find the piece of scarp paper i wrote it on.. must of pitched it

going "strictly" by memory, "think" it started out at .089. or maybe .091 .
I just kept cutting a few thou at a time, then test fit with a round til it made snug contact

Second, did you have any issues riding the slide? My PF-9 fails to return to battery if I ride it back (stopping 1/4" away). If I smack the back it goes forward all the way. However, pulling it back and letting it go always works

no issues on mine with riding the slide ...that's NOT the way to test it though.
i did it as an "extreme" test ...and it passed .
If it wouldn't of, I wouldn't of been concerned really

one thing i did do, is break the sharp point on the ext'r hook with a stone .
I didn't remove much at all..next to nothing really .
i just stoned dulled the sharp point is all

I've seen ext'rs like that dig into the case rim groove and stall a slide of other pistol platforms .
I fixed a friend's Sig that was dong that

if yours is going into battery when sling shotting and when firing, you're fine


..L.T.A.

 

[mojo-62]

Roger that on the reliability issue, I am eager to check this on my own pistiol . I've always believed there is no reason the PF9 could not be reliable with a wide variety of ammo. It's a machine it can be fixed, altered, and/or moded.

 

[Capp]

First, what is the width of the extractor now that you've removed material from it? Perhaps a numerical value would be of worth.

the more i think about, the more it may not matter what mine started at and what I took off.

due to +/- tolerance allowances , there's a condition called "tolerance stacking" that makes it nearly impossible to say "everyone needs to remove XXX amount" .

example..(completely arbitrary figures now)
the slide channel is spec'd at .095 deep +/- .003
The ext'r is spec'd at .087 wide +/- .003

One slide channel gets cut @ .092
one ext'r gets cut at .090

both parts are in spec ..one on the high side of tolerance, one on the low side.
mate them together , and "system' becomes out of spec ..that's "tolerance stacking"
and why no two pistols are "exactly" alike ...when you're dealing in mere thousandths


best to fit each part to the individual pistol "as needed"


..L.T.A.

 

[Capp]

It's a machine.

one of my mentors describes it exactly like that.

his saying;

"It's a machine, if it's made right, it has to run"

I understand what you're saying though, and agree ..any in spec ammo "should" run ..and pret' near all factory new commercial ammo is in spec according to SAAMI spec tolerances

but I'm also a realist .
a mass produced pistol , made to be mass produced as inexpensively as possible, WILL need tuned as often as not to run "every" rnd on the market .

there's tolerance stacking in pistols AND ammo

when the tolerances stack up against each other, there's only two things to do...tune/adjust the pistol to run any ammo (when possible) or adjust to an ammo that suits the pistol

I prefer the former , but I'm a backyard armorer that's had some success tuning finicky pistols .
The fellow that's not, can be just as well served, I reckon by tailoring the ammo selections


..L.T.A.

 

[Cheap_Shot]

Congratulations on the use of good trouble-shooting technique.

As you mentioned several times, you decided to change the thickness of the extractor because it didn't hold the case snug at the breechface.

That's an easy place to begin checking a FTExtract problem, but if the extractor does grip the case then move on to checking the chamber shape or the extractor spring tension.

I just want to remind everyone to find the most likely problem before modifying any parts.

 

[Capp]

i just want to remind everyone to find the most likely problem before modifying any parts.

amen!!

..l.t.a.

 

[TxCajun]

the more i think about, the more it may not matter what mine started at and what I took off.

due to +/- tolerance allowances , there's a condition called "tolerance stacking" that makes it nearly impossible to say "everyone needs to remove XXX amount" .

example..(completely arbitrary figures now)
the slide channel is spec'd at .095 deep +/- .003
The ext'r is spec'd at .087 wide +/- .003

One slide channel gets cut @ .092
one ext'r gets cut at .090

both parts are in spec ..one on the high side of tolerance, one on the low side.
mate them together , and "system' becomes out of spec ..that's "tolerance stacking"
and why no two pistols are "exactly" alike ...when you're dealing in mere thousandths

Good explanation!

best to fit each part to the individual pistol "as needed"

Which of course is not likely to happen with a pistol that wholesales for under $200. The maker must simply allow for an acceptable percentage of issues as a result of mass production and offer good warranty service to take care of those few where tolerance stacking will cause an issue.

I understand what you're saying though, and agree ..any in spec ammo "should" run ..and pret' near all factory new commercial ammo is in spec according to SAAMI spec tolerances

Which also explains ammo-selectivity, especially in certain combinations of parts on the edge of tolerance. For example, we have had members mic the dimensions of Win White Box and the variations were scary. Thus, it is often problematic in these guns while it may run fine in others. As far as dimensions for reloads, all bets are off. If you are a reasonably skilled hand-loader, you can control that. Gunshow reloads, etc... Who knows?

but I'm also a realist .
a mass produced pistol , made to be mass produced as inexpensively as possible, WILL need tuned as often as not to run "every" rnd on the market.

there's tolerance stacking in pistols AND ammo

when the tolerances stack up against each other, there's only two things to do...tune/adjust the pistol to run any ammo (when possible) or adjust to an ammo that suits the pistol

I prefer the former , but I'm a backyard armorer that's had some success tuning finicky pistols .
The fellow that's not, can be just as well served, I reckon by tailoring the ammo selections

Well yea, but only a small percentage of owners have the skill, knowlege and inclination to diagnose and tune an extractor as you did. Making matters worse, these inexpensive guns tend to attract a lot of new, inexperienced owners. From a User Group perspective, this is why we recommend the following approach to such issues:

First, rule out the easy stuff and some common user errors...
1. Is the gun properly cleaned/lubed?
2. Is the owner limpwristing (pretty common).
3. Is the owner using crappy ammo - steel, reloads, WWB, etc... (pretty common).

If there are still extraction issues that may be related to parts that don't get along well, rather than telling members here to diagnose and tune their extractor, we take an approach more suitable to the average member looking for help and advice.

1. Experiment with different ammo. Chances are pretty good that they will find a couple rounds that work fine. If so, thast's the easiest, most user-friendly approach.
2. If changing ammo doesn't help, Call KT and get a new extractor assembly. Most owners can change an extractor. There is probably at least a 50/50 chance that will cure the problem. Getting an extractor with marginal dimensions is probably not that common.
3. If none of this works, it could be the groove in the slide is too far off standard for most extractors to work. For this, you need to return the gun for service.

CONTINUED...

 

[TxCajun]

If you produce a 1000 Pf9s per week, even a 1% failure rate will put 10 problem guns out there each and every week. Anyone owner who googles Kel-tec will find KTOG in 1 click. Therefore, we sometimes see a preponderance of guns with issues. What we don't see are the other 990 that bought a perfectly funtioning PF9 and had no reason to come here and post about it. By far, most of these guns work fine out of the box. A few may require some ammo testing for best reliability. Fewer still may need a different extractor, and darn few may need a new slide.

People who are unlucky enough to get a gun with an issue like yours will often complain, "Why doesn't Kel-tec figure that out and fix the gun before they ship it." Well, at this price point they obviously are limited by time and how much measuring and custom fitting they can do. They test fire every pistol that comes off the line. Obviously the only ship the ones that pass. Again, at this price point, they obviously can't test fire every pistol with multiple brands of ammo. Kel-tec's formula relies on their excellent service department to take up the slack. I'm sure they have calculated that it is more cost effective to spend the extra time on the very few guns that need some extra TLC, rather than to invest that time in every gun that comes off the line, and would work fine as is.

 

[mojo-62]

People who are unlucky enough to get a gun with an issue like yours will often complain, "Why doesn't Kel-tec figure that out and fix the gun before they ship it." Well, at this price point they obviously are limited by time and how much measuring and custom fitting they can do. The truth is, they test fire every pistol. Again, at this price point, they obviously can't test fire every pistol with multiple brands of ammo.

Just out of curiosity, do you work for Kel Tec? Reason I ask is your inside knowledge on almost every thread subject is uncanny, you speak with such authority on the topics. Not that it matters, in fact it would be nice to know you are giving first hand account from the factory.

I'm waiting on the mail to run today on the chance that my firing pin arrives. at that point I will begin testing Capps theory on the extractor and clearance.

 

[TxCajun]

No I do not work for Kel-tec. However, I have been affiliated with this forum for 10 years and over that period, I have and still do communicate with a few folks at Kel-tec from time to time. I do know a thing or two about their SOP.

This is the internet... We get a lot of speculation and a lot of bad information posted from time to time. At KTOG, we pride ourselves in being the premier source of information on the Kel-tec brand. We try hard to keep our information accurate and reliable. When I see bad information posted here, I will do my best to correct it, every time. It is human nature, I suppose, that when someone has a problem, they tend to become a very vocal minority, and post a lot of negative non-sense that has little to do with reality. Although we sometimes get tired of injecting a dose of reality, as I said, we try to keep the information on KTOG accurate and reliable.

Capp's information on parts tolerances, tolerance stacking, etc, is very good. I just took off from there, and explained how we here at KTOG, tend to advise people based on information like his. As I said, his approach is not really, "For the Masses." The average member here probably doesn't have the knowlege or skill to take his approach, and some will even be offended if someone suggests that they have to mic and modify some part on their gun. Thus we have our appraoch, which essentially sequences trouuble-shooting from simple fixes up to warranty repair. However, I appreciate Capp's posting and his realistic attitude on the subject. People need to see that from time to time.

 

[mojo-62]

No I do not work for Kel-tec. However, I have been affiliated with this forum for 10 years and over that period, I have and still do communicate with a few folks at Kel-tec from time to time. I do know a thing or two about their SOP.

This is the internet... We get a lot of speculation and a lot of bad information posted from time to time. At KTOG, we pride ourselves in being the premier source of information on the Kel-tec brand. We try hard to keep our information accurate and reliable. When I see bad information posted here, I will do my best to correct it, every time. It is human nature, I suppose, that when someone has a problem, they tend to become a very vocal minority, and post a lot of negative non-sense that has little to do with reality. Some are worse than others. Although we sometimes get tired of injecting a dose of reality, as I said, we try to keep the information on KTOG accurate and reliable.

Capps information on parts tolerances, etc, is very good. I just took off from there, and explained how we here at KTOG, tend to advise people based on information like his.

+1, thanks for clearing things up. I figured you either worked there or had some inside info.

 

[Capp]

best to fit each part to the individual pistol "as needed"

Which of course is not likely to happen with a pistol that wholesales for under $200. The maker must simply allow for an acceptable percentage of issues as a result of mass production and offer good warranty service to take care of those few where tolerance stacking will cause an issue.

i can dig that, Tx
For the record, I wasn't suggesting anyone should expect custom fitting/tuning on a production pistol
It was just a statement that applies to any pistol, regardless of price point or platform


i also agree with most everything you posted .
The things i may disagree with are minimal , and would be little more than splitting hairs


BTW, my sig line LTA means "Love To All"
Something I really "try" to do... cause the Big Guy says we're supposed to

I have to tell you though, a friend on another discussion board (trade related) I frequent told me my sig line means "Loves To Argue"

speaking of The Big Guy, I hope ya'll have a GREAT Easter !

..l.T.A.

 

[mojo-62]

Parts arrived from KT today, They are the bomb in CS. need to go to hardware and get a small file and a 6/32 will post back later.

 

[TxCajun]

i can dig that, Tx
For the record, I wasn't suggesting anyone should expect custom fitting/tuning on a production pistol

No you didn't say that at all, which is why I agree with your very insightful post. It was good information and well explained. Many times, I have made very similar posts regarding "tolerance stacking." Usually, all parts fall within acceptable tolerances. But sometimes, two parts that must work together fall on opposite ends of the tolerances and work against each other. I usually simplify the concept by simply saying that we sometimes find parts that "don't like each other." In the case of the extractor, variances in ammunition further complicate matters, which brings about the issue of ammo-selectivity.

Obviously, with more expensive products, part of the price you pay may include more time "custom fitting" of some parts, or even tighter tolerances in machining, both of which are more expensive approaches. I would imagine that custom fitting is what Kel-tec does when a gun doesn't pass the test-firing operation, or when one is returned for service. To do that with every gun off the line would be unnecessary and would raise the price considerably causing them to loose their competitive edge. From a business standpoint, when their guns are flying off the shelves and often on backorder under their current SOP, that would make zero sense. It's probably a compromise between the engineers and the bean counters.

This is certainly not just a Kel-tec issue and it obviously goes beyond the firearms industry. Every minute an employee touches the product is money spent. To be efficient and competitive, you get the failure numbers down to where it is cheaper to spend the extra time on returned products than on all products, most of which don't need the extra attention. I think Kel-tec has a pretty good forumla in place. They are very innovative, competitive, and apparently, successful. If the reliability of their products were too far out of line with the competition, they would not be so successful. However, it is difficult to explain that to the owner who has a problem with his gun. People tend to personalize everything based upon their own experience and do not see the big picture. On forums like this, a few negative posters can easily outweight the vast majority of owners that do not even know KTOG exists.

Like most Americans, I buy a lot of different products. When they work, I almost never bother to go look for a user forum. But if I have a problem with a product, google is my friend. For example, I own two vehicles, a Camry and a Dakota. They have both been excellent vehicles but they are aging, both well over 100,000 miles. When I occassionally have an issue, I go to brand/model specifc forums for information and advice on my particular issue. OMG! All I see on those forums is people with problem vehicles. If I had looked there before buying, I would have assumed they were faulty products with poor quality control, etc. Again, they have both been excellent vehicles. Such is the nature of internet forums.

 

[Capp]

eed to go to hardware and get a small file

"If" you're attempting the mod i did...


Harbor Freight, Mo
Buy a set of needle files (couple bukz for a whole set)
You really "should' have calipers too if your pistol's ext'r needs the same as mine did.
it will be next to impossible to "guess" how much you're taking off and if you're filing straight/square and true without calipers .
(20 bukz at HF)

Only take a couple/few thousandths off at time (that's the width of a human hair)...test fit for case grip snugness..if needed, file a couple/few more thou off, test fit again .
we're only talking a hair (literally) at time


be sure to make a safe edge on the file
(grind the cutting grooves off the the thin edge)
You don't want to cut into the ext'r hook.(you'll weaken it)
You're just lowering it's position to reach a little further into the case rim


..L.T.A.