BROKEN P7M8: Part 2

[H&K 4 LIFE]

Go here for page one of the ordeal...http://hkpro.com/forum/showthread.php?t=77828

Yesterday I took my P7M8 to the range again. I was not giving this pistol the OK until I put it through it's paces and it proved itself. Well... it didn't.

The gun fired another 100rnds. of Blazer Brass with no malfunctions. Upon ending my range session with it and unloading the pistol I noticed I was getting sporadic action of the cocking mechanism. Sometimes the pistol would cock when the squeeze cocker was depressed and other times it would not. When it failed to cock, it necessitated racking the slide to get the gun to cock. This obviously didn't effect the function of the gun, as the slide is racked everytime a round is fired. Still, something wasn't right.

I took it back to the house and disassembled it. I noticed that the wing on the firing pin that the sear lever makes contact with was no longer moving as freely as it used to. I removed the firing pin bushing on the rear of the slide and low and behold it came out in two pieces. The firing pin bushing (Part #15) had been shorn completely in half!

http://img366.imageshack.us/img366/7707/dsc01735xz0.jpg

Am I upset? Only partially. I have been down this road before with this gun and never trusted it as a carry piece until it could prove itself. I would have been more pissed off if I had actually carried it. Furthurmore, the gun still operated with a broken FP bushing, so theres alot to be said for that. Also, the gun shot very tight groups as it always does so I am in no way looking to get rid of it. This is NOT a WTS thread. I was putting mag. after mag. on the 10" steel plates 75' down the end of the range. I just wish the thing would work as it was intended to.

Now we come to the question. Can I use the firing pin bushing from a PSP as a replacement for the broken one in my M8?

For all intents and purposes, the parts diagrams on HKUSA (in all their blurry, poorly laid out goodness) indicate that I can do so but I just need to make sure. HKpartsonline lists two seperate firing pin bushings (one for PSP and one for M8/M10/M13) so this has me a little worried. My dealer gave me the sear lever out of a PSP which is no doubt still in pieces in his shop and I believe he will give me the firing pin bushing as well if it is compatible with the M8.

Rant over. Thanks for reading. :5:

[JoeyBones]

Yes. The Firing Pin Bushing (entitre FP Assembly, actually) is plug-and-play, fully-compatible with the PSP and the M-Series.
It will fit and function just fine. And from what I have seen and heard, the PSP-Series bushings are actually better-built anyway (There's more metal that hasn't been milled out of the channel portion, as compared to M-Series FPB's). I've seen M-Series FPB's break before; Not certain if I've EVER seen a PSP FPB break, now that I think of it...
I routinely use a M-Series bushing in my plinker PSP, and have likewise used the PSP-Busing in my M8 while at the range.
I'm very sorry to hear of the troubles this piece is giving you!

Regards,
-Bones

[The Dread Pirate Roberts]

I have a P7M8 that is hard chromed with a crack at the same place. I have fired about 300 rounds thru it since I noticed it. The crack has gotten slightly longer since. Tried my P7 bushing in it & could not get it to fit for me. Maybe I am doing something wrong. Luckly a good family friend had one as an extra. Hope you can get it running again.

[H&K 4 LIFE]

Done. Firing pin bushing was replaced using one from a PSP. Again, all thanks to my excellent local dealer, K-5 Arms Exchange in Milford CT.

It was a bit of a pain to because you needed to cock the PSP in order to remove the FP bushing. This meant I had to first transplant the sear lever from my gun back into the PSP and then remove the FP bushing. Then I had to take the sear lever back out of the PSP and install both the sear lever and the FP bushing into my M8.

Needless to say I'm getting quite good with these guns as the whole routine only took me about 15 minutes. :)

[Greg Bell]

I would drop that gun like a stone. You have done your part, it is cursed.

[H&K 4 LIFE]

I have considered that many times my friend. :90:

[Mark71]

I have considered that many times my friend. :90:

Hopefully this will be the last of your problems with the gun. At least this time it was an easy fix.

[Sobriquet]

Get a different one. No need to give up on the model.

[H&K 4 LIFE]

Honestly, this doesn't annoy me as much as it rightfully should. Sure I'd love the pistol to work as it was intended, and finding parts is a bit of a hassle. However it is still a somewhat rare item and I know I could turn around and sell it for what I paid for it in a heartbeat. I got it for a reasonable price and I'm sure I can recoup my losses. Also, this pistol was never purchased to carry. It is a range gun and a collectors item only. I have other guns to carry and have never carried this gun except to the kitchen and back to my bedroom. :)

I'm thinking of jumping ship now before it breaks another part and while it works.

Hopefully this will be the last of your problems with the gun. At least this time it was an easy fix.

Yes but I'm slowly picking my dealers parts gun clean. I'm not sure how much more I want to pursue forcing this thing work when I could sell it and buy something else like an HK45 instead. :)

Get a different one. No need to give up on the model.

The only reason why I still have it is because it shoots so damn well. If I were to get rid of it, I probably wouldn't buy another because my uncle already owns one that I can shoot. I mainly bought it because there will come a time where there will be no more and wanted to get one before they were all gone. Also, PSP's just do not do it for me. :D

On another note. My uncle seems to think that hard chroming this gun is what has messed it up. I told him this particular P7 may have been ill effected by the hard chrome finish, or that the finish has covered up years of use. But there are too many other P7's out there with aftermarket finishes of all different types that have never broken a single part to say "it's the hard chrome that broke it". Thoughts on this?

Thanks for the comments guys. But as Greg Bell pointed out, how much longer can I keep replacing parts and hoping like hell it doesn't break again?

[Greg Bell]

Don't get me wrong, I love my P7s. A P7 was my first handgun. My M8 is my favorite pistol, and it has run without a single broken part since 1992. About 8 years ago I sent it back to HK for a rebuild (I had never even replaced the recoil spring). Hk replaced a bunch of the parts, including the barrel that they indicated I had shot-out!!! It has run without a hitch ever since.


What I am saying is, you should probably sell your, clearly cursed, M8 and get another since you really like the gun. Look for one that hasn't been hard-chromed. You never know the condition of a gun that has been HC. It could have been a rental gun, a rangemasters ammo test bed, who knows? Get another one. The biggest problem you are ever likely to see again is a hairline fracture on a bushing after after a long time. Buy 2 spare bushings and forget about it. BTW, I have never had a bushing break. If someone asked me I wouldn't have known they were a problem at all except for the net.


One last thing. Compared to other folks, I seem to have great luck regarding parts breakage. I had a trigger break on a PSP right out of the box about 10 years ago. That is it as for P7s. I have never had a USP or any of its decendants break or have any problems. I have never had a 1911 part break on me (well, I did have an ejector fall out of my gun once! Oh, and and I blew up the barrel in my Springfield) that I can recall. This is purely anectodal, but I believe that my habit of oiling the crap out of my guns is part of the reason. Plus, I have always kept my P7s (and 1911s) spotless.

[Gato]

If you shoot a P7 long enough the firing pin bushing and the DSC spring (parts 15 and 4) respectively will break.

I have an M8 which has broken both and an M13 which has broken part 4 2x and pat 15 1x.

The DSC spring seems to be sensitive to crud while I have no rhyme or reason for the bushing.

Anywho. You're not alone.

[H&K 4 LIFE]

Thanks for the reply Greg.

Besides covering up extended use and abuse is there any other way a HC finish can effect the gun? Needless to say tolerences would be tightened. Could this somehow cause parts to break as well?

My uncle now equates "HC your gun= no longer a shooter, something pretty to look at". There are just too many other P7's that run perfect with aftermarket finishes for me to agree with that. This really does seem like an isolated case and the "curse" you are descibing seems to sum it up quite nicely. :)

[Greg Bell]

No, I think HC is a great idea. Here is the pistol I described above (It was originally factory Nickel, but is now HC for about 10 years).http://web.mac.com/timetravelfoundation/The_LAMP/Gun_Pics.html#17


I think HC is a great idea. The problem is that it makes any gun look good, even a beater.

[YVK]

H&K 4 Life:

I've got an interesting bit of info to share.

I recently posted about slide cycling malfunctions my gun has experienced here http://hkpro.com/forum/showthread.php?t=82502; you actually participated in that discussion.

Yesterday, after an unremarkable 50-round range session, my firing pin bushing came out in two pieces.

So, we have a two documented occurrences now - yours and mine - when gun experiences cycling problem, and, shortly thereafter, bushing breaks.

I don't know how to line up cause-effect relationship here. Both times my pistol malfunctioned, I examined everything and bushing seem intact. In all honesty, though, it could've been compromised even then: when I examined bushing yesterday, it was obvious it broke in 3 parts, and one small fragment was missing. It is possible that the small piece broke off before my malfunctions started.

So, I have a chicken-egg dilemma here. Another possibility is "true, true and unrelated". Regardless, the only choice I have is to replace a bushing, keep shooting it and see if malfunctions come back.

BTW, any suggestions for online part source are appreciated.

[JoeyBones]

"Besides covering up extended use and abuse is there any other way a HC finish can effect the gun?"

Hydrogen Embrittlement?
I think this 'phenonemon' is generally over-publicized, but I do believe there is at least anectdotal evidence that high-temp. treatments (Melonite QPQ) and HC also, can cause embrittlement on thin metal parts (i.e. FP Bushing, sear bar, magazine floor plates). In fact, some finishers simply won't plate/treat such thin items, but rather, choose to apply black oxide (or some similarly-matched color treatment) instead.

Do a search over on the 'Cult of the P7' for "Hydrogen Embrittlement." All biases aside (You'll understand what I'm referring to once you review a few of the threads there), there is some good info there on this topic, some of which is actually provided by refinishers themselves.

Best of luck...

Regards,
-Bones

[H&K 4 LIFE]

The forum just started working for me again, so I can no reply to all the recent posts.

Greg Bell, I feel HC is a good finish as well. I don't see how you can "ruin" a perfectly working gun by doing so.

YVK, it is very possible that a broken FP bushing lead to the failure to fully return to battery. My pistol still functioned even with a broken FP bushing.

Joey Bones, your help on this subject is always appreciated. However, the sear lever, being an internal part, was not HC. I cannot really say that the condition described in your post would be the culprit given this fact. Possibly the FP bushing was ill effected, but so much parts breakage leads me to believe there are other forces at work here.

As I said before, "cursed" seems to fit the bill quite nicely.

I have decided this pistol will probably be a safe queen and may be sold in the distant future.

[Puppage]

Again, all thanks to my excellent local dealer, K-5 Arms Exchange in Milford CT.

Big Frank is a nice guy at that.....his prices? Well, that's another story.

[H&K 4 LIFE]

Big Frank is a nice guy at that.....his prices? Well, that's another story.

His service is top notch. Sure I could buy stuff elsewhere for cheaper but I rather give him the business and benefit from the excellent customer service he provides. For me it's K-5 everytime.