6br dasher=unbelievable performance!

Discussion in 'Reloading' started by goodgrouper, Apr 6, 2005.

  1. goodgrouper

    goodgrouper Well-Known Member

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    I just got through with my second load development test today with my 6br improved and I thought it was interesting how awesome this cartridge is. I fired a total of 21 different loads involving 2 powders and 3 different primers behind a 105 AMAX and out of 21 loads, 20 had a standard deviation in the <font color="blue"> SINGLE DIGITS!! </font>

    My largest group at 100 yards in thick mirage was .8" and I had several loads that were in the .2's with one going into the .1's!

    At 1000 yards in swirling wind, it had no problems hitting my 15" gong if I doped the wind right. Later on in the evening, it shot a nice 7.5 inch 6 shot group of which I was well pleased.

    I started at 30.0 grains of Varget and ran up to 32.5. 31.5 grains of Varget and a Fed205gm primer yielded an avg velocity of 2928 and an sd of 1! 32.5 grains gave 3013 fps with an sd of 6. I also tried RL15 and it shot extremely well, and was just slightly slower than Varget giving about 35 fps slower velocity with same charge.

    I bought into the suggestion on 6mmbr.com to run a cci 405 magnum primer to get an extra 100 fps more than the Fed or Win primers and I can honestly say that was a load of horse pucky. With the same charge, the cci primer was only 4 fps faster in my gun than the Fed or WIn primer. They did shoot well however, but then again, so does anything else that I want to stuff into that chamber!

    I am running about .0015 thousands clearance on this brass and use a .262 bushing for sizing.

    My barrel is 26.5" long Krieger 4 groove, 8 twist. This combo gives what I believe to be the <font color="red"> ULTIMATE 1000 yard practice </font> cartridge going. Yeah sure, my 22-250 improved fast twist drops less at 1k, and my six-five two eighty-four beats just about anything I've run it against on a windy day, but it is just a pure joy to burn only 31.5 grains of powder and hear it ping the gong at 1k every shot.

    If you are considering getting into the 1k game, and a budget keeps you from buying powder and barrels by the truckload, you should really treat yourself to the 6 br improved fast twist. /ubbthreads/images/graemlins/wink.gif

    Here is a pic of the little boom stick:
    [​IMG]
     
  2. gonehuntingagain

    gonehuntingagain Well-Known Member

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    Darn you! Now you make me want to get a new toy! /ubbthreads/images/graemlins/grin.gif
    That is a sweet gun!
     

  3. 7Rumloader

    7Rumloader Well-Known Member

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    Sweet rig man and great performance also! Thats not much of an appetite for powder at only 31 grains for all that performance either! Wish my RUM only used 31 grains!!
     
  4. Aussie

    Aussie Well-Known Member

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    Goodgrouper ,
    Is your action sleeved ? Have you blanked off the magazine ? Trying to work out whether the 6 BR will feed thru my Rem 700 mag .
     
  5. Varmint Hunter

    Varmint Hunter Well-Known Member

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    Single digit SD\'s - 95% of the time???

    Hey Greatgrouper, /ubbthreads/images/graemlins/grin.gif

    Incredible results. Just curious though; how did you prep/sort your brass and bullets to get those amazingly low (and consistently low) SD's????

    Is there a difference between the 6BR Imp and the 6Dasher"?

    Inquiring minds want to know.

    VH
     
  6. jb1000br

    jb1000br Well-Known Member

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    Re: Single digit SD\'s - 95% of the time???

    GG-- the horse pucky is for better ES, and a possibility at increased velocities -- nothing is for sure dude.

    the PATTERN is: increased velocity (cause it is a hotter primer) and better ES, not to mention better resistance of blanking.

    I have a brick BR-4's, 450's and 205ms to try when mine is together, cause i KNOW nothing is absolute in this game--use what works /ubbthreads/images/graemlins/wink.gif

    Advice was published based on the PATTERN with these rifles, kind of like 45gns of varget and a 175SMK in a 308---works for MOST, but not all /ubbthreads/images/graemlins/wink.gif

    Looks like you have something that works.

    VH--there are many different imps, the dasher seems to have the longest usable neck, and seems to be the best option if you are going to IMP a BR -- my smith just kicked a lot of arse with a dasher this weekend.

    Good luck.

    JB
     
  7. reed mosser

    reed mosser Well-Known Member

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    goodgrooper little help

    I am building a 6.5 twist 22 cal for 1000 yard shooting to shoot wildcats 100 grain bullets. I am between the 22 br the 22 brx and 22 dasher. Seeing the performance of your 6 dasher do you think the brx case will give you close to the same speed. Where did you get dies or did you make them. I was going to use a 28 inch barrel. I heard the brx and the dasher give close to the same performance, the slight edge going to the dasher. any input would be helpful good shooting nice gun
     
  8. jb1000br

    jb1000br Well-Known Member

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    Re: goodgrooper little help

    [ QUOTE ]
    I am building a 6.5 twist 22 cal for 1000 yard shooting to shoot wildcats 100 grain bullets. I am between the 22 br the 22 brx and 22 dasher. Seeing the performance of your 6 dasher do you think the brx case will give you close to the same speed. Where did you get dies or did you make them. I was going to use a 28 inch barrel. I heard the brx and the dasher give close to the same performance, the slight edge going to the dasher. any input would be helpful good shooting nice gun

    [/ QUOTE ]

    Reed--missed you at the lewistown match last time!!

    Click the link in my sig line and look at last week's Gun OF THe Week -- twas an AMAZING 22-dasher /ubbthreads/images/graemlins/wink.gif

    JB
     
  9. goodgrouper

    goodgrouper Well-Known Member

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    Yes the action is sleeved by speedy gonzales and it is a solid bottom single shot.

    From what I have read, it can and does cycle through the magazine if some slight modifications are made.
     
  10. goodgrouper

    goodgrouper Well-Known Member

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    Re: Single digit SD\'s - 95% of the time???

    I must say that it is mostly the effect of such a great design that yields such low sd's, but I will share the case prep that went into my brass.

    First, I bought 100 pieces of Lapua brass. After that, I ran them all over a .001" oversized neck mandrel. Then trimmed them all to same length. Then I squared the case heads. Then I turned the necks for a .265" neck and uniformed the primer pockets and deburred the flash holes. Contrary to popular belief, the flash holes on this brass were not perfect. WHile there was no outstanding burrs, they had a flat side on some that would have affected ignition. I also like to put a slight bevel on the flash hole because I believe it helps "funnel" the flash through to touch a wider base of the powder column.

    Anyway, after all this was done, I weighed them and found no more than .4 of a grain variation in all 100 pieces!

    After that, I just trickled in the exact amount of Varget and RL15 and seated the 105 AMAX into the jam and went shooting.

    On a side note, I chose the AMAX because of it's better explosion on varmints over the Sierra's or Bergers and I managed to test the expansion factor on a crow yesterday and the results were, well, gory!



    [ QUOTE ]
    Is there a difference between the 6BR Imp and the 6Dasher"?

    [/ QUOTE ]


    There are many versions of the improved, but the Dasher and the main improved reamer are the same. My gunsmith actually built a reamer for the 6 and 7 br imp 10 years before Dowling got credit for it, and he calls it a 6 br tejas.
     
  11. goodgrouper

    goodgrouper Well-Known Member

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    Re: Single digit SD\'s - 95% of the time???

    [ QUOTE ]
    the PATTERN is: increased velocity (cause it is a hotter primer) and better ES,

    [/ QUOTE ]

    What I was getting at was that it IS NOT a hotter primer in my experience as it gave almost exact same velocities as the Federal 205gm in every charge tried (which was 6 different charges). And it truly did give low sd's, but so did the Win wsr and Fed 205gm's. In fact, each primer at one point or another gave an sd of 1 foot per second.


    [ QUOTE ]
    not to mention better resistance of blanking.


    [/ QUOTE ]

    What is this blanking you mention?? Never heard that term before.


    [ QUOTE ]
    nothing is for sure dude.


    [/ QUOTE ]

    Absolutely! Well, one thing maybe. 6 br's rule!
     
  12. goodgrouper

    goodgrouper Well-Known Member

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    Re: goodgrooper little help

    THe brx is kindof a poor mans version of the dasher if you are going to look at it from a tooling point of view. I guess it costs more to make a reamer for the dasher, but it couldn't be too much more. A few bucks maybe. And regular br dies can be used to load the BRX, whereas you must get dasher dies for the dasher.

    I personally would still go with the dasher for your project. I believe, no scratch that, <font color="blue"> I KNOW </font> that the shaper shoulder burns the slower burning powders more efficiently for an increase of performance with the heavier bullets which is what you will be shooting.
    A great example of this is my two 22-250 improved's. One is a 14 twist for 55 grain bullets, and the other is an 8 twist for the 80 grain bullets. The slow twist shoots 55's about 200 feet per second more than a standard 22-250, but the improved fast twist shoots 80 grainers up to 400 fps faster than the standard case can get!
    THis is the whole reason why PO ackley designed his famous alteration, to utilize all the slow burning mil-surplus 4831 that was around at the time. And I say it works! /ubbthreads/images/graemlins/grin.gif

    That 22 dasher that was on 6mmbr.com last week was super efficient. It was burning about 6 grains less powder than my 22-250 imp and was getting the same velocity with only a 1 inch longer barrel! Of course, the owner stated clearly that that load would probably not work in any other rifle without blowing it up!



    [ QUOTE ]
    Where did you get dies or did you make them.

    [/ QUOTE ]

    I bought a Redding comp bushing neck die and a comp seater for the standard br and two seperate sleeves. My gunsmith then reamed the extra sleeves for the improved with the same reamer that made the chamber. With that, I can load for my standard br or my improved br and all I have to do is insert the correct sleeve. It is a very slick setup. All I had to have made was a body die for the improved, and that is also being handled by Redding.
     
  13. 4ked Horn

    4ked Horn Writers Guild

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    GG does speedy have a website? I googled sixteen ways from sunday and couldnt find one.

    Would there be any benefit in sleeving my .308?
     
  14. brian b

    brian b Well-Known Member

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    4ked horn,
    the web site is sgyrifles.com
    B