Standard or tight neck ?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Guest, Jan 22, 2003.

  1. Guest

    Guest Guest

    Picked the 6.5-284, going to use Lapua brass, throat for the middle range of the various 140gr bullets. Now, one last question. Should I go with a standard or tight necked chamber? Ray has both and I told him I didn't want to turn necks but I remember reading somewhere on this board that somebody said to go with a ".290 neck" for a 6.5 and that you could turn one neck in about a minute. Would I see a large difference in accuracy between the two? also are there any other benefits besides the potential for greater accuracy? I hope I'm not being a pain in the rear but I trust you guys for helping me with these tough decisions. Thanks again for all your help.
    Wayne
     
  2. Guest

    Guest Guest

    I would not go smaller than .292" straight for the throat dimension. The sinclair neck turner with a carbide aftermarket mandrel is the hot ticket. Make sure you tell Sinclair the shoulder angle of the cartridge, so you get the correct angle ground on your cutter.

    I think a neck diameter of a loaded round of exactly .2900" is ideal for working with the above reamer dimension of .2920"

    Having a turned and properly fitted neck does make a significant improvement in accuracy, and will not work the brass as hard, allowing you to reanneal the necks less often and get better brass life. [​IMG]
     

  3. 4mesh063

    4mesh063 Well-Known Member

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    Absolutely get the tight neck. Figure on about 10-12 thousanths of wall thickness and .0005 / side clearance. Call K&M Services for the neck turning tools. They have the nicest gizmo going. I own several and there's is the nicest I've seen. Not only a solid carbide mandrel, but the mandrel is also a reamer for removing the "dreaded donut" in your necks.

    I can't immagine anyone paying to get a gun chambered and not getting the neck smaller than SAMMI.
     
  4. Guest

    Guest Guest

    Thanks guys. Tight necked it is then.
    Wayne
     
  5. kidcoltoutlaw

    kidcoltoutlaw Well-Known Member

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    where can i find the number or web page for k & m ,thanks,keith
     
  6. Brent

    Brent Well-Known Member

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    K&M Services 717-292-3175

    I recomend the pilot jack accessory, the fluted reamer/mandrel and the Expandiron die with appropriate mandrel.

    Ken's VLD chamfering tool is sweet too.

    The power adapter is a must.

    Ken's turner does a perfect job, it's a wonder it doesn't cost twice as much too.
     
  7. kidcoltoutlaw

    kidcoltoutlaw Well-Known Member

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    i ask sinclair int. the same ? they said the only place tight necks help is close range with a light recoil gun.close would be 100 to 300 like the 6ppc is shot at i know some are using it at 1000 yards.he told me the wind and other factors would be more important than cutting necks to get the groups a few .1's smaller,thanks,keith
     
  8. Brent

    Brent Well-Known Member

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    True to a point. Evening up neck thickness will help to keep RO from becoming an issue, thus less accuracy. Combined with a tighter neck chamber, brass life in the neck area will be MUCH better, and this will also help keep neck thickness the same over time from less stretching.

    .002" total neck clearance, .003" at most, is all you need, any more than this is less than desirable, unless hunting dangerous game with the rifle. It simple over works the brass, so does bumping the shoulder back more than a thou or so... Both should be kept to an absolute minimum unless it's a DGR. Zero headspace will center up the bullet with the bore better than a tight neck, as the neck isn't laying on the bottom of the chamber and is tight to the shoulder, which centers it perfectly, zero runout is assumed.

    Hope that helps some. [​IMG]