1911A1 Puzzler......

Discussion in 'The 1911 Forum' started by Shanghai, Dec 7, 2016.

  1. Shanghai

    Shanghai Well-Known Member

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    I have a Thompson Auto Ordinance 1911A1 that I bought at some time in the 90's.

    I've been off and on at shooting it and over time I've played around at improving it, trigger job molybdenum refinish, new grips, etc. It turned out to be a good shooter and its fun to shoot.

    The puzzler is....the pin that holds the mainspring housing in the frame breaks every couple of hundred rounds. Just snaps it two. I've replaced it several times and I now order the pins in 6 packs. I can't envision that it is under any stress other than the downward pressure from the mainspring. What snaps it??


    IMG_0729.JPG
     
    Last edited: Dec 7, 2016
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  2. gdmoody

    gdmoody Moderator Supporting Member

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    What's puzzling about it?

    The picture is quite dark but from what I see, it's a good looking pistol. The grips are nice.
     
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  3. tuckerd1

    tuckerd1 Moderator Supporting Member

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    Your eyes are better than mine George. Shanghai, take some pictures outside in better light.
     
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  4. howlnmad

    howlnmad Well-Known Member

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    What's puzzling?
     
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  5. gdmoody

    gdmoody Moderator Supporting Member

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    Well, I did say the grips are nice!!
     
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  6. Alpo

    Alpo Well-Known Member

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    What picture?:confused:
     
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  7. Shanghai

    Shanghai Well-Known Member

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    The great big picture right below the wording in my post.
     
    Last edited: Dec 7, 2016
  8. gdmoody

    gdmoody Moderator Supporting Member

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    Much better picture!
     
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  9. Shanghai

    Shanghai Well-Known Member

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    I actually didn't mean to post the first on.
     
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  10. howlnmad

    howlnmad Well-Known Member

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    Have you changed the main spring?
     
  11. Shanghai

    Shanghai Well-Known Member

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    I haven't
     
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  12. jim brady

    jim brady Well-Known Member

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    The only force operating in the mainspring housing I can think of is the hammer spring. I've never had the problem you describe, and I've never read of it before. If this happens a lot, you may want to see about replacing that pin with a stronger (stainless steel?) pin.

    I guess the only question I have - and it relates to the forces acting within the mainspring housing - is about the strength of the hammer spring: Is the hammer hard or easy to manipulate? If it is "stout" - the mainspring might be a tad too strong, and that could be causing that stress in the housing and the retaining pins to snap. You don't need a super-strong hammer spring for the pistol to function reliably.
     
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  13. Shanghai

    Shanghai Well-Known Member

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    I have to apologize, Alpo. I pulled your leg a bit.

    The first pic I posted was horrible so I deleted it. Then, it took an unduly long time to take a good pic and repost. You "tuned in" between the two postings. Sorry for the snide remark but.......I couldn't resist.
     
    Last edited: Dec 8, 2016
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  14. nmckenzie

    nmckenzie Well-Known Member

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    Perhaps the conical end of the mainspring's pin is trying to wedge itself into the groove of the housing retainer pin - forcing each half of the pin in opposite directions?
     
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  15. ms6852

    ms6852 Well-Known Member

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    You might need to check the length of the strut in the hammer since you had a trigger job done. Remove the slide lower the hammer and the hammer should just be able to move back and forth a little without spring tension. If the hammer is being pushed hard against the frame you may have an oversized hammer strut which can cause binding when fully cocked.

    Now with the pistol assembled lock the slide to the rear with the slide stop. Check the hammer under the slide and see if you can move it further to the rear. This lets you know that you have a mainspring bind condition. If the hammer is tight agains the slide you have found your problem.
     
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