Sako barrel threads

Discussion in 'Gunsmithing' started by bb204, Nov 14, 2010.

  1. bb204

    bb204 Well-Known Member

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    Could anyone tell me what threads the barrel to action has, on a Sako Finnbear 7 Mag factory barrel ?
    Thanks,
     
  2. rayo9954

    rayo9954 Well-Known Member

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    According to DeHaas in the book "Bolt Action Rifles"

    Shank length: .870"
    Shank Diameter: I.000"
    Threads:16 V T.P.I.
     

  3. JUDD

    JUDD Well-Known Member

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    Be careful heard thru the grapevine they are a differant type of thread.

    Forget whats it called starts with a "W".
     
  4. shortgrass

    shortgrass Well-Known Member

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    Are you thinking "Whitworth"? Removing it and gaging the thread will tell you for sure.
     
  5. JUDD

    JUDD Well-Known Member

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    YEP!! thats the ticket!
     
    Last edited: Nov 17, 2010
  6. J E Custom

    J E Custom Well-Known Member

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    Some are Metric thread pitch and some are standard thread pitch and as suggested
    Unscrew the barrel and check the threads with a thread pitch gage to be sure.

    I'm not sure why some have the metric pitches and others have the standard pitch but
    they do.

    Some of the European threads are 55o instead of 60o also but most of these are Mauser.

    J E CUSTOM
     
  7. RJ338

    RJ338 Well-Known Member

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    If this is an L61R or an AV it is a 1.045 X16 TPI, the difference between them is the rear tang is longer on the AV. The small and medium actions use 1.00X16 on the medium and I am not familiar with the small L461 action.
     
  8. Kevin Cram

    Kevin Cram <b>SPONSOR</b>

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    The Sako L46 is a .860" x 16 tpi 55 degree Whitworth thread. I just built a .204 Ruger on one for my wife from 222 Rem Mag.
     
  9. specweldtom

    specweldtom Well-Known Member

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    The Finnbear is an L-61R, and if it is a Whitworth thread form, it will be a 55 deg V instead of a standard 60 deg V. I've read and been told that many gunsmiths use a std 60 deg threading tool to cut tenon threads for Mauser actions with the 55 deg Whitworth receiver thread.

    A thread pitch gage will tell you what the pitch is, but you may not be able to tell the difference between a 55 deg and a 60 deg form with it. Last year I had a chance to record the dimensions of a L-61R take-off barrel. The barrel thread O.D. was 1.050" diameter X 16 tpi, and the tenon was .677" long, shoulder to breech face. I never thought to check if it was a 55 deg thread form, but if it was, it wasn't obvious, because the pitch gage (std 60 deg form), fitted too well.

    I believe the previous replies had you covered, but since I had been able to measure one and record the dimensions, I decided to reply also.

    I really like the Sako actions, but JE is right. I have a .30 x .378 take-off barrel from a Sako M-995, and it's definitely a metric thread. I think the pitch on the thread is between a 16 tpi and an 18 tpi. Nothing I had matched up. I don't have a metric pitch gage to verify it.

    If you decide to rebarrel it, the L-61R is a very fine action.

    Good hunting, Tom
     
  10. RevJim

    RevJim Well-Known Member

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    So the thread on my barrel/receiver Sako AV 30-06 has "inch" threads, not metric? Just curious as it is a very nice rifle and if I ever had another 280AI or 6.5/280AI made up I would like to use this action.