Cutting chamber to match FL resizing die?

Discussion in 'Reloading' started by firstshot425, Jan 17, 2014.

  1. firstshot425

    firstshot425 Member

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    I am having a new Bartlein 7mm barrel chambered in 7mm-08 and put on my Rem 700 action. This will primarily be a hunting rifle; however, I do like to punch paper in the off season for load development, like to shoot those little bug hole groups, and want the rifle to be as accurate as possible. So, even though I am not a bench rest competitor, I am looking for better than “Hunting Accuracy”! Otherwise, I wouldn’t have even bothered with a custom build.


    I've been reading everything I can find about FL vs. NS and, although opinions vary all over the board, it seems logical to me that FL resizing would be best for accuracy and case longevity, as long as the rifle chamber closely matches your FL resizing die. I read here: (http://www.longrangehunting.com/forums/f28/resizing-full-length-neck-sizing-die-61398/index2.html) about having a custom die made to match your custom chamber.


    I currently use a three die set of Redding 7mm-08 dies. The chamber of my new barrel has not been cut yet, and I don’t know if it is even possible, but, if possible, would it make sense to have the chamber cut to match my FL Redding die?

    Looking forward to hearing your opinions on this.
    Thanks
    firstshot
     
  2. Garycrow

    Garycrow Well-Known Member

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    You'd have to get a custom reamer made and it likely wouldn't be to min spec because the reloading dies are based off of saami specs. I would think it would be much better to have a nice tight match chamber cut then have custom dies made to fit the chamber, not the other way around. I think it would come out much better and be cheaper in the long run.
     
  3. firstshot425

    firstshot425 Member

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    Thanks Garycrow
    That makes a lot of sense. I wasn't thinking about a custom reamer having to be made.

    firstshot
     
  4. Mikecr

    Mikecr Well-Known Member

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    Custom dies are very reasonable(less than top brand off the shelf).
    It's better to match chamber to your brass, then fireform brass in this chamber, then have a custom die made from the fireformed brass.
    With this and a well designed cartridge, FL-vs-NS is no longer really applicable.
     
  5. firstshot425

    firstshot425 Member

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    Just to make sure I've got this right. You fireform some brass in your newly cut match chamber and then send that fireformed brass to someone to make you a custom FL sizing die.... correct?

    Do you have any recommendations for who can make these custom FL sizing dies?
     
  6. Mikecr

    Mikecr Well-Known Member

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    You got it.

    I'm happy with JLC Precision. Jim is fast, inexpensive, and his dies work really well.
    Link at this article: Full-Length Bushing Dies and Die Conversions

    The big die makers offer this service as well. You might email one of them.
     
  7. LONGSHOOTER

    LONGSHOOTER Well-Known Member

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    Yes.
     
  8. firstshot425

    firstshot425 Member

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    would it make sense to have the chamber cut to match my FL Redding die?
    Yes? Please explain. I thought it was too costly to make a custom barrel reamer?
     
  9. Trickymissfit

    Trickymissfit Well-Known Member

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    first of all, you can cut a chamber to perfectly match the sizing die, but what for? Plus I doubt you want to spend that kind of money! Still with a modern CNC lathe you can simply program the needed information into the control. BY programing a multi pass cut you should see a chamber cut within +/-.0005", and probably as close as the dies you have. But that's also an expensive process. The other way is to program the lathe again, but cut the chamber about .010" tight. Then grind the chamber in a CNC grinder to about +/-.0002" or less. Most folks don't have that kind of money to invest.
    gary
     
  10. LONGSHOOTER

    LONGSHOOTER Well-Known Member

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    Answered via his PMs.

    Gary,

    Be careful you don't fall off into the deep. Not everyone has a CNC parked in their shed.
     
  11. firstshot425

    firstshot425 Member

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    Trickymissfit

    You're absolutely correct about not having that kind of money to invest :)

    firstshot
     
  12. tigguy

    tigguy Well-Known Member

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    Fireform some brass and have Whidden make you a set of dies and sell what you have now to make up some of the difference.
     
  13. MagnumManiac

    MagnumManiac Well-Known Member

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    I haven't read all posts, but what I have done is use a match grade chamber reamer with a standard throat length and standard neck diameter, I'm not a fan of neck turning, and have a die set made to those dimensions, any custom die set is going to cost a pretty penny.
    I have used standard dies with match grade chambers, but I use a RCBS Precision Mic for all of my handloading and set my dies up to bump the shoulder .002", never had a problem with standard cartridges, but have had problems with 3 Weatherby chambers that were cut at minimum with match grade reamers, all 3 had to have modified shell holders to get the correct shoulder bump so that the cartridges would chamber.
    Too much emphasis is placed on minimum brass manipulation, this does help, but a correctly adjusted die will and does the same job as an expensive custom set. I was a firm believer in neck sizing until hard chambering ensued which would require FL Sizing, but I found that using the RCBS Precision Mic allowed me to set up my dies for a .002" bump and it gives me the same case life as Neck sizing, I use this method on every firing, even in my 1000yrd target rifles, I sold all of my custom dies because they justvdidn't make that much of a difference, although a good seater die goes a long way to precision ammo.

    Cheers.
    gun)
     
  14. Mikecr

    Mikecr Well-Known Member

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    When case sizing doesn't go as planned it always means the plan was bad.
    MagnumManiac I hope you realize 'match grade' is meaningless, and that there is no 'standard' throat or neck (outside of SAAMI,,which is a wide band).
    Did your reamers 'match' the chosen bullets and brass in-hand?
    Were your cartridge attributes set in 1906, or did you improve on this any?

    You're wrong about brass management with custom dies -vs- the abstract that is off the shelf. And while you may get lucky enough with off the shelf dies, none of this came out of a plan.