Advantage of Metric LH thread pitch?

Discussion in 'NFA Firearms and Accessories' started by TacticalGuju, Jul 15, 2020.

  1. TacticalGuju

    TacticalGuju Member

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    This concerns 45 ACP pistols. Glock 21 to be specific.
    Is there any advantage to the metric LH thread pitch on some threaded barrels? I am debating on buying a metric LH threaded barrel & Osprey piston at my LGS vs waiting until they have a RH imperial. I heard somewhere that the LH thread pitch is more secure. Not sure what is correct. Any input is greatly appreciated. I am new to firearms.
     
  2. Prince Yamato

    Prince Yamato Member

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    My own experience is that metric left hand stays on tighter. It has the distal portion past the treads to which a rubber o-ring can attach.

    All the Austrian and German guns use LH metric threads. I’ll trust their engineering.
     
  3. mcb

    mcb Member

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    There is nothing inherent to left hand or metric threads that will make is more secure vs right hand or US Customary threads. Now there may be some validity to left hand thread and a right hand rifled barrel creating a dynamic that keep the suppressor tight but the geometry of the threads are pretty much identical between metric and USC and left and right as simple mirrors of each other.
     
    Last edited: Jul 17, 2020
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  4. 748

    748 member

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    There is none. Avoid french threads. This isn't europe, for most of us.
    Go with the simplest system you can find in the US: Imperial thread pitches, Lefty loosely, righty tighty.
     
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  5. MachIVshooter

    MachIVshooter Member

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    No advantage.

    If you live in the US, stick to the US standards, which is .578-28 (37/64-28) for .45. You'll have far more mounting options than M14.5x1 LH.
     
  6. 748

    748 member

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    I had to buy a 10x1mm thread barrel and gemtech SFN for my fiveseven pistol.
    It sucks, I can only use the 10x1 can on that gun.
    I'm just glad I wasn't an early adopter when the Gemtech SFN was selling for $1,000+.
    Got mine new at fire sale pricing for $400.
     
  7. TacticalGuju

    TacticalGuju Member

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    Thank you all for the input. I am going to order a .578X28 RH threaded barrel for the Glock 21. I hypothesize the reason for LH threads is to produce barrels that are proprietary, forcing one to purchase more adapters.
     
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  8. Sebastian the Ibis
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    Sebastian the Ibis Member

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    LH threads suck hard, with RH adapters. Are you tightening one or loosening the other?
     
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  9. Prince Yamato

    Prince Yamato Member

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    They’re standard in Europe. Honestly, I prefer them but you do pay more because they’re less common here.
     
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