300 WM Expert

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by statjunk, Apr 12, 2010.

  1. statjunk

    statjunk Well-Known Member

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    Are there any folks out there who are known to be 300 WM experts. By expert I mean they have extensive experience with the cartridge.

    I'd like to talk to someone about the rifle that I'm looking to build.

    Thanks

    Tom
     
  2. Long Time Long Ranger

    Long Time Long Ranger Well-Known Member

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    300 WM, 300 Weatherby magnum or 300 Winchester.
     

  3. LouBoyd

    LouBoyd Well-Known Member

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    Expert in what field. Expert shooter? Expert gunsmith? Expert hanloader? Expert ballistician?
    Or just a general purpose know-it-all? What's the question?

    As one of his armorers once said of Carlos Hathcock " He doesn't know much about guns but he knows how to shoot."
     
  4. statjunk

    statjunk Well-Known Member

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    300 Winchester Magnum

    Reloader, ballastician, general.

    What I'm after is setting the throat length properly for the configuration that I'm trying build.

    I'd like to talk to someone on the phone so I explain what I'm after.

    Tom
     
  5. statjunk

    statjunk Well-Known Member

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    I worked up some dummy loads. The bullet is a Nosler Accubond 180gr.

    The longer bullet is the theoretical maximum length. Essentially .308" buried in the case.

    The shorter bullet is the theoretical minimum length. It's loaded to fit a standard long action magazine well of 3.40 and is loaded to a max length of 3.385.


    Both bullets have the ogive marked. If both bullets were placed on a flat level surface the distance between the two ogive marks is the amount of throat play I have to work with.

    I attached some pictures so folks could see what I'm talking about.

    Anyone care to provide a reasoning as to where I should set the OAL with respect to ogive?

    Thanks

    Tom

    http://i213.photobucket.com/albums/cc318/statjunk/Knight Master Hunter II/IMGP0735.jpg

    http://i213.photobucket.com/albums/cc318/statjunk/Knight Master Hunter II/UpClose.jpg
     
  6. statjunk

    statjunk Well-Known Member

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    Anyone have any input on the above?

    Tom
     
  7. trueblue

    trueblue Well-Known Member

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    What would your COAL be with the boattail of the bullet set at the neck/ shoulder junction, and will that length still work in your magbox ?
    If it does, that is where I would set the ogive at.
    I shoot the 190gr Bergers out of my 300WM, so cant help you with the AB
     
  8. statjunk

    statjunk Well-Known Member

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    I'm going to be using a Wyatt's extended mag box so no issues with length.

    I can't set the base of the bullet to the shoulder neck intersection because the neck on a 300 WM is smaller than the diameter of the bullet. It's approximately .2683". Short of the .308" theoretical min amount in the case.

    I also know I need to leave some room for throat erosion.

    Another issue that I know of is that as a case nears max charge , generally speaking, accuracy increases.

    The issue I don't want to deal with is having to fill the case so full, for accuracy, that brass life and shooting comfort suffer. Also with that barrel life will suffer.

    I'm looking for a happy medium and before I choose the middle I wanted to get some thoughts from folks that have been there and done that.

    Thanks

    Tom
     
  9. statjunk

    statjunk Well-Known Member

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    Anyone? Can someone direct me to a person with experience on this matter.

    Tom
     
  10. DONTSTROKEME

    DONTSTROKEME Well-Known Member

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    Not sure if your question is way over my head or if you are complicating the issue.

    I ran the 180NAB in my 300WM with .015" jump from ogive to rifling. I belive that is the most crucial and accuracy defining area of concern. I wouldn't worry too much about the amount of bullet in the case, so long as it isn't a uber-compressed load you should be fine. I ran IMR4350 and RL22 in my 300WM and got good results with both powders.

    If I completly missed the nail head and the board please clarify what you are asking for....

    bullet jump to rifling?
    neck tension?
    best case capacity ratio for accuracy?
     
  11. Moman

    Moman Well-Known Member

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    Tom, I would talk to your smith and see what he recommends. From my recollection, the smith I used for my 300 WM suggested I set the junction of the boattail/shank to line up with the neck/shoulder junction, I think this is what Trueblue described. I couldn't do this due to magazine limitations. Anything deeper than this wouldn't increase the amount of neck contact but would help when you do start to get some erosion.

    In my case, I didn't want to put in an extended mag box. My mag box was something like 3.590 max length so I set my OAL with the 180 AB at 3.500. I had the throat set to seat at -.020. With this arrangement, I picked up a fair amount of case capacity, it feeds nice, I don't have to worry about recoil on rounds in the mag, and I have extra room to follow the throat if it starts to erode.

    Not sure if this helps with the info you're looking for, but hope it does.
     
  12. statjunk

    statjunk Well-Known Member

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    Moman,

    You did actually help me. Until now my theoretical maximum was based on the base of the bullet. However I need to sink the bullet into the case bit more because you're right it has to be base off the boat tail/shank intersection.

    I'm going to seat it deeper and see what the real difference is. I'm thinking at that point it won't matter since the difference will be much smaller.

    I realize it's a pretty big oversight on my part but at least it's one less mistake I'm not going to make.

    Thanks

    Tom
     
  13. johnnyk

    johnnyk Well-Known Member

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    statjunk,

    I think this is something that you need to talk over with the riflesmith that will be building your rifle. He can set the throat up for the load/bullet you wish to use when he's chambering your barrel. This is how I understand it anyway. JohnnyK.