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Old July 9, 2010, 12:48 PM   #1
Tankist
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Does this look normal to you?

Please take a look at attached pics.

What I have here is the interior of a H&K P7M8 slide which has been bugging me a bit lately. Since I'm rather lacking in the knowledge department when it comes to these. I was hoping that one of you fine folks can perhaps shed some light on this topic for me.

Areas marked in red seem rather out of place on this pistol and look like grind marks to me.

Would be great if someone can post a few pics of their own P7 for comparison.
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File Type: jpg 1.jpg (133.1 KB, 191 views)
File Type: jpg 2.jpg (146.0 KB, 164 views)
File Type: jpg 3.jpg (112.5 KB, 142 views)

Last edited by Tankist; July 9, 2010 at 01:03 PM.
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Old July 9, 2010, 12:51 PM   #2
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The line running through the grind marks is a crack, the grinding removed the buildup from a weld so the action would cycle. It looks like your slide has been welded, ground out, and then refinished. Hope you didn't give too much for that pistol. I wouldn't shoot it like that, but sometimes I am overly cautious (because I like my fingers).
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Old July 9, 2010, 12:58 PM   #3
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Thanks Scorch,

It was actually a very good deal and I've had it for more than a few years. Sadly, this P7 is seldom used therefore I've been pretty much ignoring it for ages.

Theres actually 2 grind marks. Why would something like this need to be done? Assuming, I would like to make it a bit more presentable, what would I be looking at to get something like this up to spec?
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Old July 9, 2010, 01:06 PM   #4
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Well, the welds would need to be redone, then the relief cuts machined out on a mill, then refinish the slide. Even then, since you put so much heat into it welding, the heat treat is possibly affected.

If it were mine, I would call HK and see what they offer to do and how much they want to do it. My bet is they would want to replace the slide, but they might want to scrap the gun. That's why you call first . . .
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Old July 9, 2010, 02:09 PM   #5
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Knowing the customer service at HK they will probelly tell you to jump off a cliff.
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Old July 9, 2010, 02:46 PM   #6
James K
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I have done some checking and concluded that the conditon pictured is normal. First, that breechblock is not machined as part of the slide. The slide is a shell of heavy sheet metal, formed and shaped with some machining; the forged breechblock is held in by lugs and welding.

The welding is normally done so neatly that most gun owners don't ever know it is there. That weld is a bit sloppier than usual, but there appears to be no problem. What appears to be a crack is a line from the forging dies.

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Old July 10, 2010, 06:52 AM   #7
mete
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That first photo shows clearly that they are weld cracks !! Grinding out and rewelding is the proper fix. You might ask on www.hkpro.com for suggestions for who could do it properly.
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Old July 10, 2010, 07:48 AM   #8
Tankist
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Thanks very much to all that responded.

A few things I managed to learn while digging around for info on this.
  • As Jim pointed out, this is factory work. This type of grind/weld work is present in all P7's
  • Breechblock is held in place by additional means other than weld.
  • Some of these lines that appear to be cracks to me may just be a line following the seam.
  • Small cracks like this are extremely common according to HK support

HKpro.com is a great source of info on HK's and I am currently awaiting account activation having just registered. I did find this thread on there with some interesting info.
http://hkpro.com/forum/showthread.ph...ght=weld+slide

I also called HK support yesterday, the nice fellow I spoke with mentioned that reports of "cracks" in these pistols is quite common and that vast majority of those sent in for examination have absolutely nothing wrong with them. I was instructed to take high res pics of the suspect areas and send to cs@heckler-koch-us.com, attention: Travis.

I am currently awaiting their reply and will post any updated info I receive.

On a side note. I did have this pistol examined by a competent gunsmith prior to purchase. I've dealt with him many times before and since and I know that there's no way he could have missed those grind/weld marks. This is mostly why it took me this long to try and dig up some info regarding this. As for the cracks in the weld being a problem or not, HK will warranty and repair weld if needed.

Last edited by Tankist; July 10, 2010 at 01:12 PM.
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Old July 10, 2010, 10:39 PM   #9
James K
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IIRC, that breechblock is supported by two big lugs that fit into the top of the slide, a bit like the barrel locking lugs on a M1911 type pistol. The welding is just to keep the breechblock in place; the lugs, not the weld, support it against the cartridge pressure.

I checked the front straight "crack" (the line ahead of the weld area) in my pistol and as best I can tell under pretty high magnification, it is not a crack but a mark from the seam of a forging die. The crack in the weld itself is a crack, but of little concern.

Jim
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