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Old November 18, 2013, 04:41 PM   #1
hodaka
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P7M8 extraction issue

After 8 years of trouble free use my pistol has begun acting up. On the past few outings, out of a box of 50, I have had 3-4 stovepipes, or even worse, the empty spins a 180 outside the chamber and jams. I thought it might improve with hotter reloads but going from 4.6 to 4.9 of 231 with 124 FMJ's did not make a difference. I've ordered an extractor spring but I've heard that these don't even need the extractor. The extractor seems very loose and you can easily lift if with your finger. I took the extractor spring out and it is there, but I have no idea how long it should be. Pistol is very clean and I have the same issue with all 3 magazines. I've fired a few thousand trouble free rounds of mostly reloads through this thing prior to the recent problems. Ejection is typically about 3 ft. at 4-5 o'clock. Have any of you experienced this problem? Thanks
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Old November 18, 2013, 04:45 PM   #2
Pilot
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I have a P7M8, and a P7 PSP and have never had ejection problems. It does sound like an ejector spring though. Replace that, and see what happens. Also, have you ever replaced your mag springs?
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Old November 18, 2013, 04:56 PM   #3
BigD_in_FL
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Is the piston completely clean? That can start to cause problems if the tube is getting gunked up
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Old November 18, 2013, 05:08 PM   #4
hodaka
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One mag is only a couple of months old. I replaced the other two springs about 3 years ago. I used the scraper tool in the cylinder and only a few specks came out. I usually use a nylon bore brush in there. The piston has the normal carbon buildup but nothing severe. Does your ejector seem really loose? Mine will hold a case but has very little tension.
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Old November 18, 2013, 05:37 PM   #5
RX-79G
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Blowback guns like the P7 don't even use the extractor. Agree that the ejector, mag or gas cylinder is more likely.

While you're at it, take a good look at the welds inside the slide.
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Old November 19, 2013, 05:40 AM   #6
In memory of dad
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Gas system

Clean the gas system! Use a 270 bore brush if you don't have the scrapper that comes with it. Great handguns and had plenty but that gas system and the weight of a 8 round handgun left me from that handgun. When the gas system fouls up to much, you won't even be able to pull the slide back so also don't see no oil in the gas system when you clean it.
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Old November 19, 2013, 02:09 PM   #7
RX-79G
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I never fouled the gas system enough to jam up the gun. I don't know how much shooting without cleaning that would require. And that includes shooting copper washed reloads.
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Old November 19, 2013, 02:13 PM   #8
MGMike
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From the symptoms you describe, the gun does not have an extraction problem; it has an ejection problem.

Either the reloads you are using are not powerful enough to drive the slide fully to the rear to smartly smack the rim against the ejector, or the extractor spring is not strong enough to hold the case against the breech face in the proper position for its rim to be hit squarely by the ejector. The gun also depends on the extractor to serve as the fulcrum for the fired case to be pivoted out the ejection port; a weak spring won't hold the extractor firmly enough.

You've said that you've already cleaned the gas cylinder and piston. Assuming they are clear, scrub out the barrel chamber to make sure that it's not retarding smooth withdrawal of the fired case, and slowing down the slide velocity, which in turn can result in weak ejection. The P7 has a fluted chamber to "float" the case out; make sure the flutes are not clogged.

Then try other ammunition; if that doesn't make the problem go away, replace the extractor spring.

Try one remedy at a time; otherwise you won't know which one was the true fix (if it happens again).

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Old November 19, 2013, 03:55 PM   #9
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I think I would first try shooting some quality factory ammo to see if the problem manifests then. If so, then there's a problem with the pistol. if not, then the problem is probably the hand loaded ammo.
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Old November 19, 2013, 05:41 PM   #10
MGMike
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Yes. That was the reason I suggested leaving extractor spring replacement until last.

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Old November 19, 2013, 06:21 PM   #11
hodaka
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Mike,

I think you used the magic word, "fulcrum". My understanding was that the P7 did not even need an extractor so I discounted the value of spring tension. Your explanation clears it up in my mind and I think that explains the extraction yet stovepiping. As I've said earlier, everything is clean and unclogged. The empty cases have very strong clear flute marks and the hole in the barrel to the cylinder is clear. It is not the ammo. Shooting the warmest loads from the Hornady site show the same characteristics as my standard load. BTW, I have been reloading for many years, have a variety of pistols, and the ammo is better than factory. Normally I would give the same advice regarding ammo. Midway has the extractor spring for $4 so that is an easy test and is on the way (along with some other stuff that I don't really need ). I will post the results in any case. The extractor spring will be easy to replace, at least the second time you take it apart. Thanks for all of the input.
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Old November 19, 2013, 06:31 PM   #12
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Quote:
From the symptoms you describe, the gun does not have an extraction problem; it has an ejection problem.

Either the reloads you are using are not powerful enough to drive the slide fully to the rear to smartly smack the rim against the ejector, or the extractor spring is not strong enough to hold the case against the breech face in the proper position for its rim to be hit squarely by the ejector. The gun also depends on the extractor to serve as the fulcrum for the fired case to be pivoted out the ejection port; a weak spring won't hold the extractor firmly enough.

You've said that you've already cleaned the gas cylinder and piston. Assuming they are clear, scrub out the barrel chamber to make sure that it's not retarding smooth withdrawal of the fired case, and slowing down the slide velocity, which in turn can result in weak ejection. The P7 has a fluted chamber to "float" the case out; make sure the flutes are not clogged.

Then try other ammunition; if that doesn't make the problem go away, replace the extractor spring.

Try one remedy at a time; otherwise you won't know which one was the true fix (if it happens again).
^^^^I think that pretty much covers it for me as well....well said Mike.
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Old November 22, 2013, 09:11 AM   #13
hodaka
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Range trip success

My spring arrived yesterday from Midway and I just got back from the range. I believe the problem is solved. Two boxes of rapid fire rounds without a single failure. Ejection is about 15 ft. to 3-4 o'clock. Much further than before. The old spring measured 0.308 and the new one is 0.338 and you can easily feel the difference with extractor tension.

It seems that the extractor on a P7 serves as a loaded chamber indicator and keeping a round in the chamber slightly compresses this spring. Since the pistol usually lives in my desk with a round in the chamber, I believe that has unnecessarily contributed to a limited lifespan of the spring. Going forward I will only chamber a round when I'm carrying it. In any case, it is a very inexpensive repair and something to keep in mind if you own one of these pistols. Thanks for all of the suggestions and I hope this helps someone.
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Old November 22, 2013, 05:50 PM   #14
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Quote:
I believe that has unnecessarily contributed to a limited lifespan of the spring.
OMG hodaka!!! What have you done? Resurrected the 'spring' debate?!!!

Oh the horror, the horror.
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