camber dimesnsions too minimum

Discussion in 'Gunsmithing' started by Lazerus, Feb 16, 2014.

  1. Lazerus

    Lazerus Active Member

    Dec 30, 2011
    About 15 years ago I had a 300 Winchester Magnum built with a 700 action and a 27 inch Lilja. This was my first build. I had a local gunsmith do it, but found out later he is pretty terrible at what he does. When I got the gun home, I quickly re-sized some brass and when I went to put the brass in and close the bolt, the bolt would not close. I took it back down and said, "What's up?" He said "You asked for a minimum dimension chamber!". He told me he took a Remington factory round and made the camber so it would just barely close on that round. Sure enough, he put it in and it barely closed. So I bought some Remington brass and out of 100 pieces I got 30 to close really nicely, some wouldn't close at all, most of them were really difficult to close. I would just bags of 100, get my 30-35 pieces that worked really well, and shoot my gun. I have tried several brands of brass and have none that will allow my bolt to close. I bought a body die by Redding and thought if I keep turning the body die down, I can probably get any piece of brass to close the bolt and fit quite well. This hasn't worked out. My gunsmith said after I had the job done, if I wanted the chamber to be bigger, it would cost me extra. I just bought 50 pieces of Nosler brass and no mater what I do with that body die, the bolt won't begin to close. Any advice or help will be much appreciated. Thanks.
  2. BountyHunter

    BountyHunter Well-Known Member

    Jun 13, 2007
    You have two choices.

    1. Order a custom smaller sizer die.

    2. Rechamber the barrel. I would not allow that knucklehead to touch it. A rechamber will probably set the barrel back 1-2 inches so that would leave you with 25-27 inches which is still good.

    3. Did you specify that small a chamber?

    BTW, a custom smaller resizing die will cost almost as much as the rechamber and you still cannot load factory.
  3. Lazerus

    Lazerus Active Member

    Dec 30, 2011
    Thanks for your response. Wouldn't it be possible to just have a gunsmith make my chamber slightly larger. Ryan from Precison rifles has done a 6.5 284 Norma for me with a Brux at 28 inches and that thing is the most accurate gun I have ever owned.If not I will just have him re-chamber it. Thanks for helping out!
  4. J E Custom

    J E Custom Well-Known Member

    Jul 29, 2004

    You can just use a SAAME reamer and head space .001 to .002 thousandths longer that the go gauge by using 1 to 2 thousandths shims between the go gauge and the bolt face.

    Any good smith should be able to do it.

  5. shortgrass

    shortgrass Well-Known Member

    Mar 31, 2010
    +1 Just have the headspace set to minimum SAAMI specs, as it should have been to begin with.
  6. Gunpoor

    Gunpoor Well-Known Member

    Apr 28, 2007
    Lazerus, I had the same problem with a factory Tikka T3 Lite in 300WSM. I ground a small amount off the skirt of the sizer die and all brass chambered without issue. You just need to move the shoulder back a little more than SAAMI spec to get them to work.
  7. MagnumManiac

    MagnumManiac Well-Known Member

    Feb 25, 2008
    An even easier method is to turn the TOP of a shell holder down by .010", this will allow the case to enter the die further and push the shoulder back by that same amount. I have a custom 375 Weatherby that this was necessary for, it works quite well.

  8. Stonewall2

    Stonewall2 Well-Known Member

    Dec 5, 2006
    It is the belt length on the brass guys.

    It is easy to make all the belts the same with a Wilson case trimmer and proper cutter.

    Get the Wilson magnum gauge to measure cases.

  9. Clark

    Clark Well-Known Member

    Oct 19, 2006
    SAAMI chambers are .220" to .227" for 300 Win Mag, 7mmRemMag, 338 WinMag, ect.

    I have never found any 300WM, 7mmRM, nor 338WM brass longer than .215".

    So I chamber my belted magnum rifles for .215".

    Most factory rifles are much closer to the SAAMI min of .220" than to the SAAMI max .227".

    With the exception of old Glock 22 40 S&W chambers, most ammo and factory chambers are at the small end of the wide and sloppy SAAMI tolerances.

    303 Brit is the sloppiest [headspace for rim + rim thickness].
    260 Rem is the tightest [neck diameter of chamber].

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