Receiver crack, is this bad?
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Thread: Receiver crack, is this bad?

  1. #1
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    Default Receiver crack, is this bad?

    Noticed this crack after a few range trips





    Does not open through to the receiver and isn't part of the cocking tube and receiver weld

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    Who is the manufactuer?

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    It looks like one of the plug welds for the cocking tube. The reason it does not appear to go through is because of the cocking tube sleeve in the reciever. When welding in the cocking tube there are typically 2 cocking tube plug welds on either side of the cocking tube through the reciever to the cocking tube sleeve. These 2 plug welds fix the tube in place at the proper cocking tube gap prior to the seam weld across the sides and top of cocking tube which without the plug welds might be inclined to shrink upon cooling changing the cocking tube gap as the seamweld shrinks. If it is just a small chunk missing out of there and not an actual crack (sorry but your pic is not letting me zoom in) then I would suspect it may just have been some weld slag in the plug weld that may have had some of the finish hiding it. Firing likely broke the slag loose leaving the "hole".

    If there is not an actual crack running off that hole and there is not a crack at the seam weld it is probably safe and pose no mechanical or safety issues.

    I would contact the manufacturer to see what they can do for you since it is a manufacturer defect. If you have someone fix it for you (again not a complicated fix either as long as not an actual crack) but the gun will need a refinishing which will add a few coin to the repair. If an actual crack emanating from that hole and not weld slag issues that would raise some more serious concerns.

    I was able to blow up the image and you can clearly see the hole drilled through the reciever for the plug weld. You can also see the discoloration from the welding around the plug weld. It appears to be a visual blemish, 1/2 the weld is there so I seriously doubt it will cause a safety or operational issue. Still contact the maker to see what they might do.
    Last edited by gulfstategaurd; 10-13-2017 at 11:32 AM.

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    @gulfstateguard thanks I'll just patch it up, I have access to a shop and mig

    Since it's not a critical part

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    Make sure you back it well with a heatsink and watch your power setting since it only needs to be a plug weld. It sucks cleaning up a burn through right there.

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    Update: I still think it's a scar from steel shrapnel, as the cocking tube usually is not plugwelded on a HK94/Mp5

    Last edited by VX666; 10-14-2017 at 07:14 AM.

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    Quote Originally Posted by VX666 View Post
    Update: I still think it's a scar from steel shrapnel, as the cocking tube usually is not plugwelded on a HK94/Mp5
    Read post #4

    https://www.hkpro.com/forum/hk-clone-...ube-welds.html

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    Visually to me it looks like a dig or pit as opposed to a crack.
    My best advice: If you are really concerned have a qualified gunsmith or HK Armorer inspect it. Otherwise just keep an eye on it, if after a few more range sessions you notice the cracks coming off of it or it becoming larger then stop and go to a gunsmith or HK armorer.

  10. #9
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    Hmm you guys could be right, a half fast plug weld chipping

    Yeah if it cracks any more on the next match I'll re-mig it

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