goodgroupers 6br imp

Discussion in 'General Discussion' started by Jimm, Aug 6, 2006.

  1. Jimm

    Jimm Writers Guild

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    GG,

    What improved version of the 6br did you build ? Also , do you think it is necessary to improve the cartridge for it to shoot good at longer ranges ? And if I may ask , what is your favorite bullet powder combo for yours at this point ?

    Thanks for your time , Jim B.
     
  2. EddieHarren

    EddieHarren Well-Known Member

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    Can't answer for GG but, I have reamers(one tight neck and one no turn) for an improved 6BR that moves the shoulder forward .070" and sharpens to 40 degrees. With an 8 twist barrel, the 107 gr VLD can be pushed to 3100 fps.
     

  3. Jimm

    Jimm Writers Guild

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    DocEd,

    Thanks for your reply , I am trying to decide whether to " improve" a 6br or build it straight up . Decisions , decisions /ubbthreads/images/graemlins/crazy.gif /ubbthreads/images/graemlins/laugh.gif

    Jim B.
     
  4. 6BR4ME2

    6BR4ME2 Well-Known Member

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    I would go with the std 6br case...for several reasons...
    one being if your just starting to play with it ...cheaper tooling costs ie dies ect. not always a good idea to start with an improved case...fire forming ect.

    the std 6br has won one world record at 1000!!!
    and a little ole 6br
    just won some wood at the 1000 yd Williamsport heavy gun class with a 15 lb gun (not 60 or 70 lbs.)world comp...
    good job jason....
    its incredable what the little cartridge is capable of.... my 10 yr old has hit a 2 moa rock at 1200 yds in bad conditions and it only burned 30 grs of powder and with a 527 BC bullet .....
    good luck
     
  5. BountyHunter

    BountyHunter Writers Guild

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    Agree go with .272 no neck turn standard br for first gun. Just get the reamer with enough freebore for the 100-108 gr Boattail bullets. I would order my own reamer from Dave Kiff at Pacific Tool and Guage for $140

    Go with a Broughton 5C barrel finished at 28 inches. No need to go longer and the 5c canted rifling is definitely 50-75 fps faster.

    Try the CCI standard and magnum primers, lapua brass and either VARGET, RL15, or VVN540 powders. Bullets either the SMKs sorted or berger 105s. Best IMO is the Clinch Rivers but good luck getting any. James Phillips on www.6mmbr.com often has some for sale ($360 per 1000) as he shoots a lot with Greg from CR a lot.

    I shot a short neck BR improved and now went to the 6mm BR DX which is Ack Imp with long neck. Same capacity as Dasher with longer neck. However, no standard dies available all custom.

    Stocks pick your type.

    BH
     
  6. Jimm

    Jimm Writers Guild

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    6br4me2, Bountyhunter,

    Thanks a bunch for your replies , I really appreciate your responses , experience like y'alls is the best for deciding things like this .

    The 6br standard is getting the go ahead . Smiths for this ?

    Jim B.
     
  7. 6BR4ME2

    6BR4ME2 Well-Known Member

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    Jimm
    good luck to you on your 6br.... good advice already given...one the funnest rounds and most accurate ever!!!
     
  8. goodgrouper

    goodgrouper Well-Known Member

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    Sorry I missed this post for awhile. I skipped right over it several times and never saw it! /ubbthreads/images/graemlins/confused.gif

    Jimm,

    I have a standard "high side turn" 6mm br and the improved version with a 40 degree shoulder. Both work great.

    I have a friend who just built a regular 6br fast twist and he noticed low standard deviations as normal with the short case, however, I had many more single digit deviations in my improved than he did with his standard. Now, that might just be a coincidence, but I had something like 23 or 24 of 26 loads that had sd's in the single digits and the few that were out were an sd of 10 or 11! This was supposed to be the design intent of the sharper shoulder-to burn slightly slower powders more efficiently with heavy bullets and with these two guns, I can see some evidence of it. However, it might be picking the fly crap out of the pepper because the standard 6br is not too hard to get uniform velos out of.

    You will have the added cost of dies, reamers, and fireforming if you choose the improved version so that's a consideration.

    BTW, my improved shoots 30.5 grains of Varget and pushes a 95 grain bullet at 3050 from a 25" barrel. My buddies gun shoots the same bullet at 2950 with 29.5 grains of Varget from a 28" barrel. Both of our rifles will get an extra 100 fps over our favorite loads but they do not shoot quite as well going that much faster. Something to think about.

    Also, I tried all the small rifle primers with my optimum charge of varget and the Federal 205gm's gave the best accuracy. The CCI primers were touted to give more velo but they shot almost the same speed as the Fed's. I had a hard time getting the oversized CCI primers into the extra tight Lapua Br brass primer pockets too so I just went back to the Fed's.

    Ps. If you do go with the improved version, I have all the info you need to have to get the right gear and it will be less painful for you than it was for me! /ubbthreads/images/graemlins/wink.gif
     
  9. goodgrouper

    goodgrouper Well-Known Member

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    I can probably get some pictures of both cartridges side by side on here if you would like.
     
  10. jb1000br

    jb1000br Well-Known Member

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    Hi Jim -- the std .272nk 6BR has treated me well this year--> http://www.6mmbr.com/gunweek070.html

    last 3 10-shot groups at 1000 yards (in a match)

    4.7" 99
    6.9" 97
    7.3" 96

    106CR's and a LOT of R15 pushing about 2975 at the muzzle.


    But then again, a 6Dasher just re-set our 10-shot light gun record again at near 3.85" (previosly 4.27 with a std. 6BR) /ubbthreads/images/graemlins/shocked.gif

    p.s. as far as SD's are concerned, they don't always mean much on paper...I had a chronoed 10-shot group at 1K show me 8fps ES...group was over 12" tall /ubbthreads/images/graemlins/shocked.gif 'splain that one /ubbthreads/images/graemlins/wink.gif (obviously out of tune eh?)

    JB
     
  11. Jimm

    Jimm Writers Guild

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    GG ,

    Thanks for all the info. I am looking forward to building one . Already have stock for it ( figured stock #111 on Richard Franklins website )

    Jim B.
     
  12. Jimm

    Jimm Writers Guild

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    JB,

    Man, I wish I could shoot that good ,congrats on the group!!

    Jim Brown
     
  13. 6BR4ME2

    6BR4ME2 Well-Known Member

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    Jimm,, again std 6br....jb I have tryed your williamsport load the last 4 or 5 days and it shows no signs of pressure !!!!!

    All I can say is its just as fun shooting the clay for your sighter at a 1000 yds as it is to shoot a sub MOA group at a 1000...seeing your impact on the little clay and watching it explode on impact is as big a thrill....no offense to this site at all but he link Jb gave you has tons of info....ya the 6dasher now has a pending world record!!!
     
  14. jb1000br

    jb1000br Well-Known Member

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    6br4me2: do you shoot a w-port? who are you? send me an email to the address in my profile.

    No pressure with my 1K load! WOW /ubbthreads/images/graemlins/shocked.gif I am shooting a loosy-goosy broughton 5C (0.2432" x 0.2372")and still get ejector marks...but it shoots so darn good...tried a few tweaks for this weekend...

    JB