Necking up .243

Discussion in 'Ammunition & Reloading' started by Hot Sauce NARC, Feb 3, 2010.

  1. Hot Sauce NARC

    Hot Sauce NARC New Member

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    I just droped a down payment on a custom 260 Remington and i was planning on using lapua brass but lapua doesn't make it in 260 so my gunsmith suggested necking up 243 lapua brass. I got out of the shop and i forgot to ask him who makes the dies i need to complete this operation. I assume these aren't all that uncommon?

    And if your going to suggest that i neck down from 308 explain yourself and maybe you will convince me
     
  2. robocop10mm

    robocop10mm Lifetime Supporting Member Lifetime Supporter

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    If you are using virgin brass, simply champher the mouth and ease it over the expander ball. The Lyman die is probably best for this with their long tapered expander. I don't recall how much shoulder difference there is, but fireforming will give the best accuracy.
    When necking up you may get thin necks, check accordingly.
    The .308 can be necked down with the same caveats except you can end up with overly thick necks. Outside neck turning will give the best performance, just for unifomity if nothing else.

    Before trying either operation with once fired brass, anneal to avoid splits.

    Thread killed before 1900 hrs, sorry.
     

  3. cpttango30

    cpttango30 New Member

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    Necking down a 308 case will be a better bet. It will put less stress on the brass. You end up with slightly longer brass and slightly thicker necks. This is a good thing and allows you to outside turn the necks for a nice tight fit.

    With lesser brass you take a chance of splitting the brass when expanding.

    As for dies I prefer Hornady and RCBS. Hornady dies have the tear drooped shaped expander ball like mentioned by Robo.

    Like Robo said anneal fired brass. This can be done a few ways. If you want to go big go get a brass-o-matic and do it that way. Or do it the poor mans way.

    1. Get 9x12" cake pan (Steel from wife)
    2. Fill with water enough to cover bottom 1/3 of the case.
    3. light up propane or MAPP torch and heat necks evenly and then knock them over into the water.

    My method.
    1. gather brass.
    2. light up torch.
    3. done mechanix ware gloves or something thin like that.
    4. hold brass in finger and heat neck while rotating brass in fingers. If you burn your fingers you went too long.
    5. drop in bucket of water.

    NOTE: if using hand held method I found dipping fingers of gloves in water slightly will help when annealing 200+ cases.
     
  4. Hot Sauce NARC

    Hot Sauce NARC New Member

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    Thanks guys.

    Im still pretty new to this so forgive me if this is a stupid question, but do i need a special neck expander die or can i just run .243 brass up a .260rem full length sizer to expand the neck? Still kind of confused.
     
  5. cpttango30

    cpttango30 New Member

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    The only time you really need a special set of dies is when you are going from say a 30 cal to a 22 cal. That is a lot of brass movement and you will have a set of dies custom made for that job. Just one or 2 calibers no worries just remember to lube it good. I would use imperial sizing wax.
     
  6. Hot Sauce NARC

    Hot Sauce NARC New Member

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  7. robocop10mm

    robocop10mm Lifetime Supporting Member Lifetime Supporter

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    Annealing must heat the neck to cherry red to be effective. I use the pan of water method so the case head is protected from the softening effects.

    I said specifically to champher the mouths of the .243's to allow the expander ball to enter with out splitting the mouth. I have necked .30-06 brass down to .25-06 and .25-06 UP to .30-06. I have sized .243 up to .308. I have sized .257 Roberts up to 7X57. I have sized 6mm Rem and .270 Win up to 8X57.

    When going up more than one size, I do it progressively. I have expanders in .257, .277, .284, .308 and .323. I have only split one neck and have never collapsed a case.