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Gunsmithing Bolt handle fix #2

LRI

Lance Criminal
Full Member
Minuteman
  • Mar 14, 2010
    6,308
    7,386
    52
    Sturgis, S. Dakota
    www.longriflesinc.com
    This one came to us from one of our dealers. I guess the owner took it somewhere to have the handle swept, it failed, and the attempt to reattach it didn't go so well, and it failed again. There are some "Yuks" in this thing that I'll have to be dealt with first. Wire-feed welders and bolt guns aren't the best bedfellows.

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    Cancer be gone!

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    The "test zap." A small tack weld for mockup to verify timing and position. It's pretty good so we'll move along.

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    Root passes to fill from the bottom up. This way there's some actual "spine" in the weld.

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    Root and fill passes complete, onto the mill. This job begs for the 4th axis as it makes the workholding a snap and I'll be able to access multiple faces in a single setup.

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    Fluff n buff on a scotchbrite wheel. One more saved from the grave. I see two little pimples that I need to go back and sand out. I missed those.

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    Last edited:
    Is that mung on the scope rail the next project? Great job on the handle!
     
    How many hours do you have in reattaching the bolt handle?
     
    Looks great Chad, really nice work.
    How do you keep the heat from multiple pass welding from negatively affecting the temper in that area of the bolt, heat sink, re-temper or is that not an issue?
     
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    Reactions: Jscb1b
    Looks great Chad, really nice work.
    How do you keep the heat from multiple pass welding from negatively affecting the temper in that area of the bolt, heat sink, re-temper or is that not an issue?

    It's just a matter of patience more than anything. Tig stuff doesn't get too crazy, provided you give it some time between passes. I was asked earlier how much time I had spent on this repair. Most of that 2-1/2 hours boiled down to zapping a stitch and wandering off to do something else for a few minutes. Truth be told, there isn't a lot going on back there that demands any hardness. I suppose if I got the cam surface for the cocking piece or the PE cam scorching hot, it could start to gall, but I've soldered a few thousand M700's now, and while the backmost portion of the bolt does get quite warm, I've never had a problem.
     
    So you don't do a full pass at a time?

    A root pass on this thing was maybe 3/8" of an inch long. There's a fair amount of mass there. At 90 amps with 3/32 filler rod it goes pretty quickly. Zap, go suck on a coffee cup, come back, and repeat. Towards the end, it might have gotten warm as the welds got a little dull. These were surface blends just to get material on the corners so that they'd finish with good definition when I cleaned everything up. Even still, the action functions great, and there's no indication of anything trying to cannibalize itself.