Matching throat angle to Berger VLD bullet?

Discussion in 'Gunsmithing' started by NW Hunter, Feb 25, 2010.

  1. NW Hunter

    NW Hunter Well-Known Member

    Messages:
    372
    Joined:
    Jan 29, 2010
    Hi guys, can anyone share their experience on throat reaming a chamber to match the secant ogive of a Berger VLD bullet? I've got a Bartlein barrel with 11.25 twist on order for my 300 wm.
    1) Do you see a big gain in accuracy with the throat matched to the Bergers?
    2) Will tangent ogive bullets still shoot accurately with the throat matched to a Berger ogive?

    I've always shot Barnes, but I am going to start load development with the Bergers.
     
  2. NW Hunter

    NW Hunter Well-Known Member

    Messages:
    372
    Joined:
    Jan 29, 2010
    Wow! I thought this would be a hot topic! Does anybody have any thoughts or experiences good or bad about custom throating? Come on out of the woodworks and help me hash this out.
     

  3. coyotezapper

    coyotezapper Well-Known Member

    Messages:
    696
    Joined:
    Sep 26, 2009
    Berger VLD's normally like to be seated to the lands for best accuracy. This at times can be a problem with magazines or detachable box mags. By having your barrel throated for the VLD's you can determine the "over all length" with reamer selection/design. If I were you I would seat a VLD to the ideal length to fit your magazine and send it to Dave Kiff at Pacific Tool and Gauge and have him grind you a reamer off of that sample. He may already have a reamer drawn for your bullet/cartridge application. What you are doing here is setting your freebore. I have done it and it works great. As far as shooting other bullet designs through that custom chamber I am not sure how that would work. I shoot only the bullets I have the rifle chambered/throated for. There could be seating depth issues with tangent ogives. ALL that being said I shoot 180 VLD's in a stock M700(7MM STW) with a detachable mag which only alows me to seat the bullet to 3.65" COAL and the bullet jumps .220" to the lands!! It will shoot in the .6's all day long at 3000 fps. Go figure. Remmember also that if you ever plan to sell a rifle, that it may be harder to sell with a unique throat. Kind of like match rifles with tight neck chambers where neck turning is required.
     
  4. NW Hunter

    NW Hunter Well-Known Member

    Messages:
    372
    Joined:
    Jan 29, 2010
    Thanks for your imput Coyotezapper. You make some valid points. I too wonder about seating depths of other buulets with a custom throating. I'll probably start with a standard chamber initially, then go with a custom throated chamber when the barrel needs to be set back. Hopefully by then I will know what I want to shoot!

    Does anyone else have any other experiences to share on the subject?
     
  5. lazylabs

    lazylabs Well-Known Member

    Messages:
    870
    Joined:
    Oct 26, 2006
    If you are considering that I would buy a reamer with no throat and then two different throaters, little cheaper that way. If your talking about a shallower throat angle for vld's it will erode faster than a steeper throat.
     
  6. NW Hunter

    NW Hunter Well-Known Member

    Messages:
    372
    Joined:
    Jan 29, 2010
    lightbulbLazylabs, you just saved me some $$. Throat erosion is what got me into this in the first place! Thank you for your insight.