New cw380 first shots

[skiflydive]

I've had a P380 for a few years that functions fine. I recently bought a CW380 that had feed issues right out of the box after I did the regular prep...the cartridge rims weren't sliding up the breech face. I rounded the bottom of the extractor which helped a little and filed the extractor post which helped a little more. Still had feed issues though. I had read in this forum about shortening the rear extractor pin to reduce the tension. I took the P380 apart and measured the extractor pins and spring with a caliper for a total stack length of 1.878". The same parts in the CW380 measured 1.913" for a difference of .035". I took .020" off the back pin reducing the total stack to 1.893" and now the CW380 runs like a champ.

[mpgo4th]

Great help guys thanks. I’m going to tackle mine today. If I mess up I have part coming already.


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[Ed M]

This has been an interesting thread, to say the least.

Thanks to some fine detective work by markman, the root cause of many Kahr 380 feed problems may have been identified.

It'd be a lot easier to identify "problem" guns during the assembly process by simply measuring the extractor tension.

Kahr could easily set up a measuring system, and use it for both the initial assembly process, and also for their repair system process.

Certainly would be easier to modify the rear pin, than messing with extractor dimensions.

Perhaps Kahr should be made aware of this information - it might save a lot of headaches for both customers and Kahr themselves.

[markman]

This has been an interesting thread, to say the least.

Thanks to some fine detective work by markman, the root cause of many Kahr 380 feed problems may have been identified.

It'd be a lot easier to identify "problem" guns during the assembly process by simply measuring the extractor tension.

Kahr could easily set up a measuring system, and use it for both the initial assembly process, and also for their repair system process.

Certainly would be easier to modify the rear pin, than messing with extractor dimensions.

Perhaps Kahr should be made aware of this information - it might save a lot of headaches for both customers and Kahr themselves.

I beleive this has been posted here long before I arrived. All the 1911 gunsmiths have been doing this for ages. This is also a problem with some Kahr 9's and 40's also. And like I said earlier, this might not be the only problem, but I would start here first since it is so easy to check.

[markman]

Thanks. Also when you get time if you could post the photos of how you used the scale to measure extractor tension.

I hope this helps. I have an easier time doing it than try to explain it to someone else. I'm sure there are other ways to do it, but I just tried to use what I had available to get the job done. I used my CM9 for the pics but it will work on any Kahr or any other pistol.


I get a spent case with the primer removed and slide it up under the extractor from the bottom. I center the primer pocket over the striker hole so it sits about where it normally should when it's chambered.




I stand a 1/4" x 2" hex head cap screw head down on my postal scale and zero it.



Then I slowly pushed the empty case from under the extractor with the slide off the pistol and upside down while watching the read out. It has to be slow & steady. I also try to keep the bolt as close to the breech face and under the rim as much as possible so it doesn't bind the case for a more accurate reading. It took me a few tries before I got the hang of it, but when you get the feel, you'll get consistent readings.



Personally, I would check this before I dissembled any pistol to modify it. If somebody here sees an easier or better way to do it, I'm all ears.

[Ed M]

Yeah, but you brought the info to the surface again, and added some good info as well. You at least deserve a "well done".

Just out of curiosity, you mentioned that you took too much material off the back of a pin. Did you actually test this and get FTE problems, or just go by your tension measurements?

I really like the idea of being able to do a simple tension check (say 2 lb ideal on a 380) versus just blindly grinding away on stuff.

[markman]

Just out of curiosity, you mentioned that you took too much material off the back of a pin. Did you actually test this and get FTE problems, or just go by your tension measurements?

The tension was way too low so I just started with another rear pin. I didn't want to even try it and if it failed go through the whole process again for a $2 pin.

I really like the idea of being able to do a simple tension check (say 2 lb ideal on a 380) versus just blindly grinding away on stuff.

That's also the reason I won't just measure the whole assembly and compare it to others. Like I explained earlier with the tolerance stacking. Your not taking into account the spring rates, pocket depth in the rear slide cover, the location of the pocket machined in the slide where the extractor pivots, etc etc etc. It's too dam easy just to measure the tension. On the tension, I try to get it as close as possible without getting anal. My wife says I have tendencies to go that way, go figure.

[Ed M]

IMHO, this thread deserves "sticky" status. Too much good info to just get lost in the shuffle, so to speak.

[dustnchips]

Great pictures and description Marksman. If I ever run into trouble I will certainly try this. As an aside, when I was doing my prep work I smoothed and polished the breach face on my CW380. After what Marksman has posted I can see where this might have reduced the friction between the casing and the shell base. Shortening the back pin to get the right tension makes sense, but what's done is done and mine works fine.

[Bawanna]

IMHO, this thread deserves "sticky" status. Too much good info to just get lost in the shuffle, so to speak.

Done!