Convert Win M70 458 WM to 458 Lott

Discussion in 'Gunsmithing' started by nksmfamjp, Sep 12, 2019.

  1. nksmfamjp

    nksmfamjp AH Senior Member

    Joined:
    Jan 28, 2019
    Messages:
    95
    Video/Photo:
    2
    Likes Received:
    35
    Location:
    Central OH
    Hunted:
    MT, OH
    Can you recommend a gunsmith to convert a Win 70 safari 458 wm to 458 Lott...rechamber, confirm/smooth feeding, possibly add recoil reducer?

    I’d prefer OH, but I’m willing to ship.
     

  2. WAB

    WAB AH Elite

    Joined:
    Oct 8, 2015
    Messages:
    1,165
    Video/Photo:
    64
    Likes Received:
    1,912
    Location:
    Alabama
    Member of:
    DSC, NRA, SCI
    Hunted:
    Zambia, Botswana, Mozambique, South Africa, Zimbabwe, Scotland, England, Canada, Alaska, Ireland
    I used Gary Junk in Fairbanks AK. He did a great job on the conversion, cutting the barrel down to 22”, installing banded front sight and sling swivel, etc. Gary is semi retired but I think he still keeps Arctic Gunworks contact info alive.
     

  3. BnC 04

    BnC 04 GOLD SUPPORTER AH Fanatic

    Joined:
    Jan 30, 2011
    Messages:
    792
    Video/Photo:
    9
    Likes Received:
    606
    Location:
    Tennessee
    Member of:
    DSC, RMEF, DU, NWTF, NRA
    Hunted:
    Canada/Europe/Africa/14 US States
    Wild West Guns in Anchorage, AK did 1 of my conversions for me. Did an excellent job and haven't had any issues whatsoever in numerous hunts with it.
     

  4. 375 Ruger Fan

    375 Ruger Fan AH ENABLER GOLD SUPPORTER AH Legend

    Joined:
    Jun 14, 2015
    Messages:
    2,977
    Video/Photo:
    195
    Likes Received:
    3,731
    Location:
    Houston, Texas
    Member of:
    NRA, DSC
    Hunted:
    Namibia, Zimbabwe, New Zealand, South Africa (Eastern Cape & NW), Alaska, TX, LA, MO, OH, MT, ID, WA, Canada (Yukon)
    Dennis Olson in MT did my M70 conversion to make a 404 Jeffery and did a great job at a reasonable cost.

    500 1st Street
    Plains, MT 59859
    Phone: (406) 826-3790
     

  5. TOBY458

    TOBY458 AH Elite

    Joined:
    Jan 23, 2014
    Messages:
    1,245
    Video/Photo:
    93
    Likes Received:
    1,452
    Location:
    Madison Georgia, USA
    SSK Industries in Winterville OH. has done excellent work for me. Give JD Jones a call.
     

  6. TOBY458

    TOBY458 AH Elite

    Joined:
    Jan 23, 2014
    Messages:
    1,245
    Video/Photo:
    93
    Likes Received:
    1,452
    Location:
    Madison Georgia, USA
    If you get this done, let us know how much it costs and how well it works. I have a Model 70 458 as well.
     

  7. nksmfamjp

    nksmfamjp AH Senior Member

    Joined:
    Jan 28, 2019
    Messages:
    95
    Video/Photo:
    2
    Likes Received:
    35
    Location:
    Central OH
    Hunted:
    MT, OH
    Rifle is on its way to Mr. Olson.....I’m excited!
     
    375 Ruger Fan likes this.

  8. DrBob

    DrBob New Member

    Joined:
    May 12, 2018
    Messages:
    3
    Video/Photo:
    1
    Likes Received:
    5
    Location:
    ALASKA
    Hunted:
    Zim
    For those that are expert at reloading there is another option... swap out your short magazine, follower,ejector and bolt stop for ones from 375 H&H. You can then handload to 3.6" length. In 2009, I published an article about this in Magnum Magazine in South Africa. I used the Pressure Trace system to measure pressures and Johan Loubser from Western helped with powder selection since he had been a ballistics expert at Somchem. I used a Winchester M70 in 458, a CZ 500 in 458, a Ruger No. 1 in 458 and for reference of both the "458 XL" and Lott .. a Ruger Magnum rifle in 458 Lott.

    Attached are parts of the article from 12/2009 and a pic of the Cape I shot with the CZ550 with the 458XL cartridge. Magnum Magazine 2009_1.jpg Magnum Magazine 2009_2.jpg P8080113.JPG
     
    C.W. Richter and Ridgewalker like this.

  9. nksmfamjp

    nksmfamjp AH Senior Member

    Joined:
    Jan 28, 2019
    Messages:
    95
    Video/Photo:
    2
    Likes Received:
    35
    Location:
    Central OH
    Hunted:
    MT, OH
    I have had several suggestions to do this, but why not just go to the larger standard round with known load data.
     

  10. DrBob

    DrBob New Member

    Joined:
    May 12, 2018
    Messages:
    3
    Video/Photo:
    1
    Likes Received:
    5
    Location:
    ALASKA
    Hunted:
    Zim
    Load data is essentially the same. Using H335 and Fed215 primers... 82 grains in the XL yielded 2248 fps and the Lott 2291. The extra neck tension probably being the reason. There is one good point to rechambering a 458 into Lott. During the workup, the Ruger Lott could not use all of the bullets out to length as with the Trophy Bonded Bearclaw. The 458 could. The conversion to 458 Lott still required that same parts swap out. The XL has a niche though. In some countries, rechambering means re-registering with all the hassle and risks. I am attaching the published loads developed with the usual points that this is with this rifle and all handloading must be judicious. Follow the rules. Loads.jpg
     

  11. DrBob

    DrBob New Member

    Joined:
    May 12, 2018
    Messages:
    3
    Video/Photo:
    1
    Likes Received:
    5
    Location:
    ALASKA
    Hunted:
    Zim
    Here is additional data from article loads 2.jpg loads 3.jpg
     

  12. nksmfamjp

    nksmfamjp AH Senior Member

    Joined:
    Jan 28, 2019
    Messages:
    95
    Video/Photo:
    2
    Likes Received:
    35
    Location:
    Central OH
    Hunted:
    MT, OH
    One thing I did notice is that a Lott reamer won’t completely recut a WM chamber.

    The WM has a super long 29 min lead while the Lott has a short throat and 2 deg lead....interesting

    How well does shooting WM in a Lott work? I wonder for deer hunting in Ohio...
     

  13. bruce moulds

    bruce moulds AH Elite

    Joined:
    Aug 10, 2018
    Messages:
    1,014
    Likes Received:
    844
    and those leade angles make a big difference to pressures.
    going from 1/2 degree to 2 degrees can make a safe load blow primers, even with a longer throat.
    don't ask me how I know this.
    bruce.
     

  14. nksmfamjp

    nksmfamjp AH Senior Member

    Joined:
    Jan 28, 2019
    Messages:
    95
    Video/Photo:
    2
    Likes Received:
    35
    Location:
    Central OH
    Hunted:
    MT, OH
    Yea, but this is kind of opposite, right? Like a normal 458 Lott goes from throat diameter to bore at a steeper 2deg angle. On a conversation, it will go 2deg to the remaining 29 min throat....should lower pressure slightly and guide bullet to bore more accurately!
     

Share This Page

 
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice