PDA

View Full Version : CM9 Extractor is Hammered (Pictures) - Any One See This Before



gmcjetpilot
03-30-2016, 03:07 PM
Anyone see this.
Is this normal. Is this something you have to replace often?
To me this should be hitting only brass, and steel should be the winner.

http://i1088.photobucket.com/albums/i328/gmcjetpilot/CM9%20Extractor%20Damage_zpsycpruxu6.jpg

Alfonse
03-30-2016, 04:00 PM
I happened to have one sitting on my desk, with thousands of rounds through it. I only fire brass though. Steel case ammo might be a different story. Looks fine, but is a bit dirty.

https://lakelinellc.com/wp-content/uploads/2016/03/Extractor.jpg

gmcjetpilot
04-24-2016, 08:46 PM
I happened to have one sitting on my desk, with thousands of rounds through it. I only fire brass though. Steel case ammo might be a different story. Looks fine, but is a bit dirty. THANKS.... yep I cleaned it, polished it and it did not look too bad and put it back together.

I am disappointed in KAHR...They never got back to me... I sent them a request.

The part is $16 I recall... So I am going to by a new one. The extractor is scoring or making the rim of the brass. Since I reload this is not good to have these deep scratches in the rim....

gb6491
04-25-2016, 06:45 AM
Anyone see this.
Is this normal. Is this something you have to replace often?
To me this should be hitting only brass, and steel should be the winner.

http://i1088.photobucket.com/albums/i328/gmcjetpilot/CM9%20Extractor%20Damage_zpsycpruxu6.jpg
To me, that looks like damage that might occur from rounds feeding ahead of the extractor or from dropping the slide on a round already in the chamber.
Regards,
Greg

muggsy
04-25-2016, 07:42 AM
Good eye, Greg. I was going to say the same thing. You should never put a round in the chamber and then drop the slide.

gmcjetpilot
04-27-2016, 07:18 PM
To me, that looks like damage that might occur from rounds feeding ahead of the extractor or from dropping the slide on a round already in the chamber.
Regards,
Greg


Good eye, Greg. I was going to say the same thing. You should never put a round in the chamber and then drop the slide.

Thanks for the input Gents, but that is speculation on your part I can address. I have never dropped a round in the chamber. I know better.
I only go into battery one way and one way only, I lock slide back, insert magazine with bullets (brass case), release slide. For more data
I shoot standard 115gr FMJ for practice and premium LEO Federal or Speer JHP on rare occasion. Also FYI in 500-600 rounds I have never
had a misfire... So I am doing something right, rough edge to extractor or not.

UPDATE, to Kahrs credit they are sending me a new extractor with a return envelope to send old one back for analysis.
I well informed in mechanical engineering and metallurgy by education and profession. Brass will not do this to hardened
steel.

Bills1873
04-27-2016, 08:28 PM
Could it have been that way from the factory?

gb6491
04-27-2016, 08:56 PM
Thanks for the input Gents, but that is speculation on your part I can address. I have never dropped a round in the chamber. I know better.
I only go into battery one way and one way only, I lock slide back, insert magazine with bullets (brass case), release slide. For more data
I shoot standard 115gr FMJ for practice and premium LEO Federal or Speer JHP on rare occasion. Also FYI in 500-600 rounds I have never
had a misfire... So I am doing something right, rough edge to extractor or not.

UPDATE, to Kahrs credit they are sending me a new extractor with a return envelope to send old one back for analysis.
I well informed in mechanical engineering and metallurgy by education and profession. Brass will not do this to hardened
steel.
Thank you for the clarifying how you chamber rounds gmcjetpilot.
Not having the part on hand to examine closely, we must speculate given the evidence in your photos. Your photos suggest to me that there is damage to the edges of the extractor, but I can't tell definitively if the edges are deformed or chipped.
I've not tested an extractor to verify whether they are hardened or not. Have you? I'd very much appreciate hearing your results if you have.
For the sake of argument, let's say that it is hardened.
One way knife makers test hardened blades is to press the flat of the edge against a brass rod. This can result in a deformed edge, chipped edge, or an unaffected edge.
I'll not argue that the edges of the extractor are thicker than most knife blade edges, but given the correct conditions (enough force, shock, etc.) I think it plausible that the edges of the extractor could react in a similar manner.
With that in mind and from the location of the damage on your extractor, I still believe this is could be caused by rounds feeding ahead of the extractor (and I'd be checking my pistol to see if it was push feeding).
Then again, I may be way off base with the above. So, kudos to Kahr for sending the part and I'm pulling for it to fix your issue.
Regards,
Greg

Bobshouse
04-28-2016, 08:54 AM
I happened to have one sitting on my desk, with thousands of rounds through it. I only fire brass though. Steel case ammo might be a different story. Looks fine, but is a bit dirty.

https://lakelinellc.com/wp-content/uploads/2016/03/Extractor.jpg

I say that puppie needs to soak in some gun cleaner for a few days and scrubbed with a stiff wire brush. If the rest of your gun looks similar, maybe just throw the whole thing in there and let it soak. With the already tight tolerances of the Kahr, your clogging the drain so to speak.

Alfonse
04-28-2016, 09:50 AM
I say that puppie needs to soak in some gun cleaner for a few days and scrubbed with a stiff wire brush. If the rest of your gun looks similar, maybe just throw the whole thing in there and let it soak. With the already tight tolerances of the Kahr, your clogging the drain so to speak.

The extractors self-clean. By putting it on my desk, I was hoping it would clean the whole thing....

Bawanna
04-28-2016, 10:15 AM
That's a fine idea.

b4uqzme
04-28-2016, 10:56 AM
The extractors self-clean. By putting it on my desk, I was hoping it would clean the whole thing....

Mrs b4 seems to have the same idea for our entire house.

Bobshouse
04-28-2016, 11:22 AM
Mrs b4 seems to have the same idea for our entire house.

We have a deal at our house, its 50/50 for everything, including cleaning the house. She cleans the inside, my son cleans the outside and I dirty it back up. I know, I know, that's not 50/50 but if I didn't do my part they would miss out.

CJB
04-28-2016, 04:47 PM
Let me say something about dropping the slide on a chambered round, and its supposed disastrous effect on the extractor.

This is a matter of hyperbolic lore.

Here's where it came from, and it does have some basis, but you decide. Back in the day, we had 1911's and Browning HP's, and probably some others, whose extractor ran through a hole, a tunnel if you will. The extractor was not spring steel, but rather springy for the short distance that it could move. On both of JMB's designs mentioned, the thinnest, and weakest, part of the extractor was at the cut made where the groove in the cartridge case was caught.

Herein is the basis for the lore. As designed, on a clean pistol, the extractor could run over cartridge rims all day along and suffer no harm. It was designed to do so. It has a nice angular nose which pushes the extractor sideways allowing it to ride over the cartridge. However, given a dirty 1911, or dirty early HP, if that tunnel was filled with crud, well... there was no place for the extractor to actually move into. Apply force at the thinnest weakest part, don't let it move sideways, and something has got to give. The extractor on those models, and others built similarly, can break. The breakage was exasperated by the careful fitting given to extractors by the AMU, on target built (bullseye) 1911's, where the cut in the extractor was often deepened, so that very weak recoil springs could be used with very weak loads. They wanted no interference from the extractor causing issues with chambering, so if needed, the cut was made deeper. This eliminated the extractor having to move sideways slightly just to chamber a cartridge. If anyone cares to do the research, its available in several (outdated) publications by the Armed Forces Press, and in some old American Riflemen magazines. Do some searching on articles by Hatcher.

FN redesigned the extractor on the HP to a pivoting one, and it eliminates the problem, as also does the various external extractor types seen on some 1911 derivative designs.

Kahr's "self cleaning" is about as self cleaning as any other external extractor, which means no gunk in the tunnel, and assurance of easy movement.

Keep in mind, every Remington 700 and similar rifles have extractors that ride over the rim of the cartridge as part of normal functioning. Keep in mind that many autoloading rifles do as well, such as the AR-15 and AR-10, etc. These show almost no failures in service.

This bit of lore, falls into the same category as "never dry fire" a weapon.

With all the warnings Ruger gives, falling just short of "Do not eat the firearm", they never once mention dropping the slide on a loading chamber as being harmful. Neither does Colt. Neither does Kahr. Neither does FN, Walther, or Browning.

Be willing to bet that extractor was deformed when new.

But, y'all can believe what you want.

Alfonse
04-28-2016, 06:44 PM
CJB must be right. My desk still isn't clean.

gb6491
04-28-2016, 06:46 PM
Interesting post cjb. I'm not totally on-board with with all you wrote, but will keep it in mind. However, I do now tend to agree with you that the extractor in question was deformed when new. I say this because after reading your post I decided to look at this from a system view vice just looking at the part. Doing that and given how the extractor sits in the slide (had to go take a closer look) I don't see how anything could come into contact with that trailing edge with enough force to cause any damage there.
Regards,
Greg

BTW, what I'm not on board with is that while, as you point out, many modern extractor systems have a built in tolerance to being snapped straight over a rim, I still believe it is not a good idea to get into the habit of dropping the slide of a controlled feed pistol on to a chambered round. I'd also point out there can be other things to consider: I.E. Springfield Armory advises not to manually load rounds into the chamber of their XD series of pistols and I'm guessing that this has to do with the LCI they use.
Anyway, thanks for the lesson :) Oh, almost forgot, I still believe steel can be damaged by brass.....But, y'all can believe what you want. :p:D:hippie:

gb6491
04-28-2016, 06:48 PM
CJB must be right. My desk still isn't clean.
LOL, I just posted along the same line.
Regards,
Greg

CJB
04-28-2016, 07:36 PM
Desk cleaning is available..... But youd needa put up with my accent.

Bills1873
04-28-2016, 08:06 PM
Could it have been that way from the factory?
Hmmmm?

CJB
04-28-2016, 08:45 PM
Interesting post cjb. I'm not totally on-board with with all you wrote, but will keep it in mind. However, I do now tend to agree with you that the extractor in question was deformed when new. I say this because after reading your post I decided to look at this from a system view vice just looking at the part. Doing that and given how the extractor sits in the slide (had to go take a closer look) I don't see how anything could come into contact with that trailing edge with enough force to cause any damage there.
Regards,
Greg

BTW, what I'm not on board with is that while, as you point out, many modern extractor systems have a built in tolerance to being snapped straight over a rim, I still believe it is not a good idea to get into the habit of dropping the slide of a controlled feed pistol on to a chambered round. I'd also point out there can be other things to consider: I.E. Springfield Armory advises not to manually load rounds into the chamber of their XD series of pistols and I'm guessing that this has to do with the LCI they use.
Anyway, thanks for the lesson :) Oh, almost forgot, I still believe steel can be damaged by brass.....But, y'all can believe what you want. :p:D:hippie:

Fair enuf!

Hey in a friendly way, have you ever wondered if all those controlled feeding cycles are actually that, or have some of them, in cases where the bullet has jumped forward a bit from the magazine... being pushed in by the extractor instead of the boltface? Food for pondering.

gb6491
04-28-2016, 09:05 PM
Could it have been that way from the factory?


Hmmmm?
http://www.rooney.org/tlc/smileys/huge-not-worthy.gif:D:hippie:

Alfonse
04-28-2016, 09:08 PM
I must hate cleaning my desk, since I have always kept it a mess. With only one part to look at, it is hard to know what happened. It could have been in a bunch dropped on the factory floor and run over with a fork lift.

I don't recall seeing a photo of an extractor that looks quite like the OP's. I had my MK9 slide detail stripped today, and it looked like the photo I posted earlier, but maybe not quite as dirty.

When operating any machine, I do try to manipulate it in a way that causes the least damage or wear that is still conducive to what I am trying to do with it.

This has been a great discussion of the Kahr extractor and did get me thinking in a bunch more detail about how it functions and what its environment might be.

Thanks!

gb6491
04-28-2016, 09:18 PM
Fair enuf!

Hey in a friendly way, have you ever wondered if all those controlled feeding cycles are actually that, or have some of them, in cases where the bullet has jumped forward a bit from the magazine... being pushed in by the extractor instead of the boltface? Food for pondering.
It wouldn't surprise me if some did get push fed. I have pushed rounds as far forward as possible in my CW45 and they all still fed up under the extractor, but that's hand racking them. I have a little Casio camera that can do 1000fps, might have to set it up and do some experimenting.
Regards,
Greg

CJB
04-28-2016, 09:28 PM
Do it!