REAMERS Breaking

Discussion in 'Advanced Gunsmithing & Engineering' started by Rustystud, Oct 6, 2017.

  1. JRS

    JRS Silver $$ Contributor

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    Jim Borden was a "Professional Mechanical Engineer", and happens to be a reputable machinist.
     
  2. Eddie Harren

    Eddie Harren Gold $$ Contributor

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    Then his actions should have been "PME" instead of "TPE".
     
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  3. X Ring Accuracy

    X Ring Accuracy Site $$ Sponsor

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    I'm grabbing the beer and popcorn for this one :D
     
  4. msalm

    msalm

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    I've had two break in the last two years. Same deal with one flute breaking off. I predrill and bore leaving .015" or so for the reamer to clean up. Pilot is always solidly on the lands and contact at the rear of the chamber to provide alignment. I can say without question there was no overload on the reamer itself. The one flute just popped off. One was within .100" of headspace so I polished the sharp corners at the end of the fractures and finished the chamber while standing on eggshells. Chamber turned out fine. This was a straight 284 so it had pretty deep flutes and thin webs.

    As for the reamers not cutting an all flutes, they certainly should. They are ground at less than equal spacing to minimize chatter yes, but they are all the same dimension and should all cut equally if ground properly. If all flutes were spaced evenly they would set up a resonance of sorts, imagine a reamer digging in and every flute hitting the 'hiccup' at the same moment. It would get bad real fast.
     
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  5. hogpatrol

    hogpatrol Gold $$ Contributor

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    My .02, rebranded crap Chinese or other cheap foreign reamer blanks or tool steel.
     
  6. DaveTooley

    DaveTooley Silver $$ Contributor

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    I've broken one reamer. I knew it wouldn't make it as soon as it touched steel. A 17 Mach IV. Very thin flutes and a small diameter core. It would grab and twist. Nothing I could do but wait for the crash. I worked with Dave Manson when he was still running Clymer to work out some problems I was having. I was having a bitch of time making sizing dies. The issue was every angle on the reamer changed as soon as it touch steel. You could watch the reamer twist from the load. He increased the diameter of the core and made the flutes thicker. Pretty much eliminated my problems. Everything is a compromise so the fix reduced the chip capacity of the reamer.
     
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  7. X Ring Accuracy

    X Ring Accuracy Site $$ Sponsor

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    This is what I was trying to say on my reply way back before the mud slinging started. Thanks Dave for putting it into the correct terms : )
     
  8. clowdis

    clowdis

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    Dammit!! Just broke a flute off a .260 reamer that I've had for 15 years! So it isn't the steel that they're using to make the reamers. Wonder if the barrel makers have changed something in the steels they are using?
     
  9. carlsbad

    carlsbad Details matter. Silver $$ Contributor

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    Maybe the electricity running the lathe has changed--dammed solar power.

    Sorry to hear that. How many barrels on the reamer? was it sharp?

    --jerry
     
  10. clowdis

    clowdis

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    Dunno, maybe 25 barrels. I think it is sharp and the chamber was bored to within 1/4 inch before putting the reamer in it. So I don't think there was undue stress on the reamer flute.
     
  11. MDSpencer

    MDSpencer

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    M-2, M-7 and M-42 are the steels used. 62-64 Rc.
     

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