Hydroforming 6bra

Discussion in '6BR, 6BR Improved & Wildcats' started by cast1, Sep 24, 2017.

  1. cast1

    cast1

    Joined:
    Jan 10, 2017
    Messages:
    31
    Anything wrong with getting a hydroforming die from Hornady to preform the brass for 6 bra or is it a waste?
     
  2. Alex Wheeler

    Alex Wheeler Gold $$ Contributor

    Joined:
    Feb 5, 2011
    Messages:
    4,937
    Its a waste. You need 100 rounds down your barrel before you start really tuning anyhow.
     
    Sniper338 and LRPV like this.
  3. pat fulghum

    pat fulghum Gold $$ Contributor

    Joined:
    Apr 12, 2016
    Messages:
    166
    My $.02 worth

    Buy 200 pieces of brass.
    Buy a 8# jug of H4895
    Buy 1# of varget
    Buy 2000 cci 450’s
    Buy one 6Bra Barrel
    Buy 2000 105 hybrid (or Berger 108 or VT103)

    start low and work up to just under 30gr varget .. form 200 brass..this load will shoot very well so don’t waste it just shooting You have a little Varget left but not much

    Now take the H4895 tune your load you should get 1900 rounds with that jug o powder.

    Your brass will have 10firings, you are out of that lot of powder, you are out of bullets, primers are almost gone, barrel close to done

    (You could buy 10 1# of h4895 and stretch it out a bit)

    Remember how much fun you had.
    Remember what you learned. (You wrote it all down right ;))


    Open up the wallet and start over with new lot of powder, brass, primers, bullets, and get a new barrel

    Almost works out perfectly :)
     
    nakneker, painter, kvd and 10 others like this.
  4. PMA3

    PMA3 Gold $$ Contributor

    Joined:
    Dec 24, 2010
    Messages:
    279
    Pat,

    Why did you choose Varget as the fire forming powder? Could you also use H-4895, IMR 4166 or RL-15, which are all faster burners?

    Paul
     
  5. pat fulghum

    pat fulghum Gold $$ Contributor

    Joined:
    Apr 12, 2016
    Messages:
    166
    Why? ... Just trying to be nice to the brass on the first firing.... it will take 2 firings to fully form.
     
  6. BT1

    BT1 Silver $$ Contributor

    Joined:
    Nov 23, 2010
    Messages:
    267
    Used 30 gn of H4895 for FFing. Very accurate. Good enough for club matches. Have fun with those first rounds. Did jam 0.010 just to be sure with 105 Hybrids. Now use the VTs for matches and closer to 31 gn of H4895.
     
  7. kvd

    kvd Silver $$ Contributor

    Joined:
    Aug 13, 2011
    Messages:
    194
    Great post - good analysis of component usage with some humor thrown in. Love it!

    If I may pass on a typing tip: if you want to type a cent symbol (¢), on PC computers, hold down the ALT key and type the number 155 on the number pad. The old ASCII codes won't work on the numbers above the letters - only the number pad.

    Ken
     
    painter and dogdude like this.
  8. Clancy

    Clancy Silver $$ Contributor

    Joined:
    Nov 25, 2012
    Messages:
    320
    Alex I think you're very sharp, but I don't understand. I've seen guys posting ones and twos fireforming regularly here. Why wouldn't it be just that much better with nearly formed brass?

    Understandable that the barrel will change after 100 or so, but just curious why it's a waste?
     
  9. Alex Wheeler

    Alex Wheeler Gold $$ Contributor

    Joined:
    Feb 5, 2011
    Messages:
    4,937
    Any testing before 100 or so is wasted.
     
  10. Clancy

    Clancy Silver $$ Contributor

    Joined:
    Nov 25, 2012
    Messages:
    320
    I've got an ultimatum short action I was planning to build a precision rifle type BRA on. If I might as well be shooting them in the dirt, I think I might load some ELDs and coyote hunt with it this winter, then start looking for a hybrid load.
     
  11. dogdude

    dogdude Egan O'Brien Gold $$ Contributor

    Joined:
    Feb 20, 2009
    Messages:
    540
    ¢ haa, it works, Thanks' Ken
     
  12. Ghansen

    Ghansen

    Joined:
    Dec 31, 2013
    Messages:
    127
    I've just hydro-formed some 6mmGrinch, and I am happy with a two step process that makes "factory" brass for me.

    1st stage, run your press up to the forming die, and using your feeler gauges to space +10thou for your initial hydro-forming. This leaves a rounded shoulder to finish forming and gives you reasonable and consistent initial case length

    after you have finished hydro-forming the batch

    2nd Stage, dry the cases and take the 10thou out and seat the forming die against the shell holder, with light lube and no water run the case up into the hydro die to finish forming the neck and shoulder. This took a few thou off the case length but very uniform results without using components.

    You can always experiment a bit to get your own best fit, but this worked for me with the standard Whidden die and chambers as good as bought stuff.
     
    Last edited: Sep 30, 2017
  13. kvd

    kvd Silver $$ Contributor

    Joined:
    Aug 13, 2011
    Messages:
    194
    Some other useful codes:

    Degree symbol ° = ALT 248
    Plus/minus ± = ALT 241

    Do a google search for American Standard Codes for Information Interchange (ASCII) codes and you can find tables that list all the codes. Kind of strange that these old codes developed in the 1960's are live and well in your PC.

    Now back to the OP's question. I believe (I have not fire formed yet) that the 6mm BR case fits snugly enough in the 6BRA chamber that the only thing hydroforming would accomplish is changing the shoulder angle from 30° to 40° which is not worth the time and expense versus just fire forming.

    Ken
     
    Last edited: Sep 30, 2017
    dogdude likes this.
  14. DocDoc

    DocDoc

    Joined:
    Aug 21, 2012
    Messages:
    58
    That is the point of the AI, the chamber is .004 less than the parent, so the parent cartridge is held back against the bolt face for ideal fire forming.
     
    boltfluter likes this.

Share This Page